Bartomeu made the announcement on Tuesday in a speech confirming he and Barca's board of directors are resigning.
"We accept entry into a European Super League of football clubs," he said. "This acceptance will have to be ratified by the next assembly. We have also approved the format of the new Club World Cup.
"The European Super League will make it so the club can remain being one of the members."
A report from Sky Sports last week claimed Liverpool and Manchester United were leading talks around the prospect of a new FIFA-backed tournament featuring the world's biggest clubs.
It was claimed more than a dozen teams from England, France, Germany, Italy and Spain were in negotiations to become founder members of a possible European Premier League backed by $6billion (£4.6billion) of funding.
Bartomeu's comments made it clear that Barca are one such club to have been approached to join the proposed competition, which could start as early as 2022 and comprise home and away fixtures between 18 teams.
Any final decision would have to be ratified by a vote held by the next Barca president and board of directors.
In his speech, Bartomeu did not state whether Barca's involvement in any new such competition would lead to them withdrawing from LaLiga or the Champions League.
The new Club World Cup was scheduled to begin next year, in place of the traditional pre-World Cup tournament, the Confederations Cup, with FIFA expanding the tournament to 24 teams and China selected as host.
The coronavirus pandemic means the event is likely to be pushed back until at least 2022, however.
Bartomeu's admission that Barca have accepted the plans for the new tournament is at odds with the view of the European Club Association (ECA), which last year produced a letter insisting "no ECA clubs would take part".
Writing on Twitter on Tuesday after Bartomeu's resignation speech, LaLiga president Javier Tebas said: "Unlucky Bartomeu, announcing on the final day participation in a phantom competition that would be the ruin of Barcelona, and ratifies his ignorance in the football industry.
"A sad end for a president who had success and, in the end, errors."
Bartomeu made the announcement on Tuesday in a speech confirming he and Barca's board of directors are resigning.
"We accept entry into a European Super League of football clubs," he said. "This acceptance will have to be ratified by the next assembly. We have approved the format of the new Club World Cup.
"The European Super League will make it so the club can remain being one of the members."
Spain has been in a state of alarm since March 14 and remains one of the countries to be worst-hit by the spread of COVID-19, with 4,154 confirmed deaths.
LaLiga has been suspended indefinitely, with the RFEF having announced on Monday that professional football in Spain would only resume when the government give the go-ahead.
It was reported on Wednesday that Barca's squad refused to take a 70 per cent pay cut and the club, after a meeting of the board, have now confirmed they have filed a Temporary Employment Regulation File (ERTE) process.
The ERTE will impact both sports staff – including the men's senior squad and all professional teams – and non-sports staff.
"Among the measures adopted, it's worth noting those related to the workplace are motivated by the need to adapt the contractual obligations of the club staff to the new and temporary circumstances that we are experiencing," a Barca statement read.
"It is about the presentation of the different relative files in the sporting field (football and other professional sports), as well as for the rest of the non-sporting personnel.
"These files will be processed before the Treball Department of the Generalitat de Catalunya, once the club has shared all aspects related to these measures, and their scope, with all its staff, both sporting and non-sporting.
"Basically, it is a reduction of the working day, imposed by the circumstances and the protection measures carried out, and, as a consequence, the proportional reduction of the remuneration provided for in the respective contracts.
"Measures that the club wants to implement scrupulously follow the formal labour regulations, under the criteria of proportionality, and above all fairness, and with the sole objective of resuming the activity of the club as soon as possible."
Barca have also announced a number of initiatives they are launching in an attempt to help combat the pandemic.
Club facilities have been made available to the Health Department of the Generalitat de Catalunya, while the Barca Innovation Hub has been opened up as a research centre for local hospitals and clinics.
Barca confirmed a massive wage cut to help the club during the coronavirus pandemic, with players agreeing to reduce their salaries by 70 per cent and making further financial contributions to ensure all employees are able to take home the full value of their wages.
The news came following reports of a disagreement between senior Barca players and club directors over the degree of wage reduction, with Messi denying the squad turned down the team's proposal to reduce salaries.
Bartomeu said Messi never opposed Barca's decision to carry out salary cuts, telling SPORT: "Messi told me from day one that this reduction had to be made.
"This proposal came from the captains. It is a gesture that demonstrates their commitment to the club."
Messi issued a statement on behalf of the players on Monday, which was soon shared by other members of the first-team squad, in which he insisted they had always been happy to reduce their pay in order to help the club and its staff during the nationwide lockdown, with LaLiga under indefinite suspension while Spain attempts to arrest the spread of COVID-19.
The message accused those in charge of Barca of placing the players under unfair levels of scrutiny while negotiations over wage cuts continued.
Bartomeu added: "Perhaps [the players] have been frustrated by things said by people inside and outside the club, who do not have all the information.
"But the negotiations were carried out only by Oscar Grau and me and we have not said anything."
Barcelona announced on Monday they would take legal action against Rousaud after his claims "someone had their hand in the till" at the club – allegations that were strongly rebuffed.
Unbowed, Rousaud – one of six members of Josep Maria Bartomeu's board to resign last week – issued a statement via Mundo Deportivo declaring his readiness for a court battle if necessary.
It read: "For the sole purpose of responding to the announcement made by the FC Barcelona spokesperson about filing a criminal complaint against me for the statements made regarding the so-called 'BarcaGate' case, I want to state the following:
"1. The existence of corruption within the club is evident in the fact that it has already been shown that contracts between related companies…
"2. The statements I made regarding this matter are absolutely true and demonstrable; the opinions that I have expressed are absolutely well-founded, which allows me to state that the announced complaint has no basis whatsoever.
"3. Unfortunately, when I made the club aware of these irregularities it became the cause of my resignation. However, it cannot be underestimated that there is a moral – and legal – obligation to publicly report irregular actions that may constitute crime."
Over the course of six points in total, Rousaud confirmed the matter was now in the hands of his legal representatives, while insisting he has "never questioned the honourability of our beloved club and its employees".
Bartomeu is not obliged to call elections until 2021, when he will not be able to stand, although there is a growing demand for him to bring the date forward.
The Barca president's standing has been weakened in recent months over apparent clashes with Lionel Messi over the star player's future at the club and the handling of pay cuts given to the squad in response to the coronavirus pandemic.
Rousaud, Enrique Tombas, Silvio Elias, Josep Pont, Jordi Calsamiglia and Maria Texidor stepped down amid this climate of mounting tension.
Prospective candidate Victor Font, leader of the Si al futur group seeking to take control of the Camp Nou boardroom, issued an open letter at the weekend that claimed Barcelona were at risk of "economic bankruptcy" and that "moral decay" had set in at the club.
Like Rousaud, Font questioned Barca's alleged agreement with the PR company 13 Ventures, which purportedly ran social media campaigns to boost Bartomeu's standing and disparage current and former players critical of his regime. Both Barcelona and 13 Ventures deny the claims.
On Monday, Bartomeu's board reshuffle was confirmed by Barcelona. Jordi Moix, Pau Vilanova and Oriol Tomas took on vice-presidential briefs, with Marta Plana secretary of the board of directors and David Bellver becoming treasurer. Javier Bordas is the manager responsible for first-team football, with Xavier Vilajoana overseeing Barca B, youth teams and women's football.
Messi is contracted to Barca until 2021 but a report emerged on Thursday claiming the six-time Ballon d'Or winner wants to leave next year.
The superstar captain put question marks over his future to one side on Sunday, producing a masterclass in Barca's 4-1 LaLiga rout of Villarreal.
Messi reached 19 LaLiga assists for the season – his best tally in Spain's top flight – and Bartomeu was asked about the 33-year-old post-match.
"I am not going to explain the details of what is happening every week. There are negotiations with many players," Bartomeu told Movistar.
"Messi has always expressed that he wants to end his career at Barcelona."
Bartomeu was also asked about under-fire head coach Quique Setien after Barca stayed within four points of bitter rivals Real Madrid with four games remaining.
Two-time defending champions Barca are on track to be dethroned by Madrid this season, with Setien reportedly set to be axed.
But Bartomeu said: "I know there are rumours. It is totally false.
"Quique Setien has the confidence of everyone, of the players, of the board, he is doing a great job.
"There are four games left and then we have the Champions League. We have important games to play this season."
Barca face bottom side Espanyol in Wednesday's LaLiga derby.
Barca confirmed a deal with Las Palmas to sign the highly rated 17-year-old in September 2019, but he stayed at the second-tier club for the remainder of the campaign.
He was finally unveiled as a Barcelona player on Thursday, however, with president Josep Maria Bartomeu and new sporting director Ramon Planes – who has replaced Eric Abidal in the role – present at the ceremony.
Pedri – who revealed he idolises Andres Iniesta – is excited at the prospect of working alongside Messi, provided the forward remains at Camp Nou amid continued speculation over his future.
"It's not every day you can sign for this club," Pedri said.
"I'm really looking forward to doing great things, but the pressure is the worst a footballer can have. You have to get rid of it as soon as possible and replace it with excitement.
He added: "My idol has always been Andres Iniesta and now I want to learn from the best, which is Leo Messi."
As for his own situation, Pedri is planning for life at Barca but is also prepared for a temporary move away, a spell out on loan potentially offering him the chance to play regularly and aid his long-term development.
"The first option is to stay here and have fun with the best, although a transfer is not an option that I've ruled out," he admitted.
"You have to take [pressure] off from the first moment. You must have enthusiasm to enjoy each day and hope that everything goes well."
It has been a busy week for Bartomeu and Barca, who parted ways with Quique Setien after the humbling Champions League exit to Bayern Munich that has increased concerns Messi may leave.
Ronald Koeman has since been appointed as head coach, while presidential elections have also been moved forward to March 2021.
"With Pedri we bring in one of the most talented players of his generation and a Barca fan since he was a child," Bartomeu tweeted, along with a picture of him stood alongside the club's new recruit.
"He brings the excitement and ambition we need for this new project and to be a success at Barca."
