General Growth Properties Inc. said its biggest debt and equity holders have offered to jointly invest $3.93 billion in the company, bolstering a plan with Brookfield Asset Management Inc. to bring the mall owner out of bankruptcy.

The investments from Bruce Berkowitz’s Fairholme Capital Management LLC and William Ackman’s Pershing Square Capital Management LP would allow unsecured creditors to be paid in full with cash, General Growth said in a statement. Their funds are in addition to $2.63 billion pledged by Brookfield.

The cash payment matches a provision of a competing bid by Indianapolis-based Simon Property Group Inc., which has offered to buy its biggest competitor for more than $10 billion and pay all unsecured creditors. Chicago-based General Growth rejected that bid and lined up the Brookfield investment last month with plans to split into two companies, part of a proposal that creditors called risky because of a reliance on debt and equity sales.

“If BAM moves ahead with this structure, it removes most if not all uncertainly from their previous bid, and removes any doubt to whether it’s credible or not,” said Jim Sullivan, an analyst at Green Street Advisors in Newport Beach, Calif.

New York-based Pershing Square is General Growth’s biggest equity investor, with a 25-percent economic interest, including 7.5 percent of its shares. Fairholme is the largest creditor with about $1.9 billion of General Growth debt, while Brookfield has about $500 million and Pershing Square owns about $434 million, according to a person familiar with the investments.

Brookfield’s new plan calls for Fairholme and Pershing to buy about 380 million new General Growth shares at $10 each. The investments would combine with 250 million shares Brookfield would buy, $1.5 billion in new debt Brookfield is raising, and a $250 million rights offering for a new company, General Growth Opportunities. Brookfield will backstop $125 million of that sale, and Fairholme and Pershing Square will backstop the rest. Combined, more than $8 billion would be raised.

“The proposal from Fairholme and Pershing Square builds on the significant momentum we have created to return GGP to a strong financial foundation for the future,” General Growth CEO Adam Metz said in the statement. “Our goal is to raise capital in the most cost-efficient way to maximize value for all of our stakeholders. We are pleased with the support shown by one of our largest unsecured debt holders and one of our largest equity holders.”

The proposal must be approved by General Growth’s board and the bankruptcy court, and better offers may still emerge, the company said. Also, General Growth would have the right to reduce the $3.8 billion investment by $1.9 billion should it be able to raise equity capital on better terms.

Ackman stepped down from General Growth’s board as part of the plan, the company said.

“Bill Ackman has made significant contributions to GGP during his time on the Board,” Metz said. “We understand his decision to resign to facilitate Pershing Square’s participation in this proposal.”

Simon Property spokesman Les Morris declined to comment.

Brookfield’s plan gives General Growth equity holders $15 a share, compared with about $9 a share under Simon’s offer. The previous version of Brookfield’s plan called for General Growth to raise as much as $5.8 billion by issuing shares and new debt and through the sale of properties.

The new plan “would, if accepted, deliver substantially all of the cash required to fulfill the company’s capital needs in connection with its emergence from bankruptcy and provide unsecured creditors with par plus accrued interest in cash,” General Growth said.

Unsecured creditors said in a March 2 bankruptcy-court filing that the previous plan was too risky. Simon, in a separate filing, supported the creditors.

“While Simon has offered to pay unsecured creditors in full in cash, the consideration to be offered to unsecured creditors under the ‘recapitalization’ is entirely subject to market risk,” David C. Bryan, Eric M. Rosof and Emil A. Kleinhaus, Simon’s attorneys, wrote in the filing. “If General Growth does not raise enough money to pay unsecured creditors, they will be stuck with the equity securities of a highly leveraged company.”

David Fick, an analyst with Stifel Nicolaus & Co. in Baltimore, said the new plan is likely an effort to compel Simon to boost its offer.

“These guys don’t have the ability to run these assets without the existing GGP management,” he said. “The Pershing Square and Brookfield interests are best aligned with getting a sale done.”

General Growth, owner of New York’s South Street Seaport and Boston’s Faneuil Hall, filed the largest real-estate bankruptcy in U.S. history in April after amassing $27 billion in debt making acquisitions. Under its plan with Brookfield, General Growth would split into a company owning shopping malls and another that would own buildings and land with redevelopment possibilities.