U.S. banking regulators have asked prospective buyers of struggling Texas bank Guaranty Financial Group to submit bids by Monday, the Financial Times reported, citing people familiar with the matter.

Regulators are hoping that three banks that had bid for Colonial Bank -- Canada's Toronto Dominion, JPMorgan and Spain's BBVA -- will step in to bid for Guaranty, the paper reported on its website on Sunday.

The Federal Deposit Insurance Corp on Friday shuttered Alabama lender Colonial. About $22 billion of Colonial's assets will be sold to BB&T Corp, a southeast regional bank.

JPMorgan and TD had expressed interest in Guaranty, which has also drawn interest from other regional banks, the paper reported, citing unidentified sources.

A private equity consortium, which includes Blackstone Group LP, Carlyle, Oak Hill Capital, TPG and the Texas banker Gerald Ford, is also considering a bid for Guaranty, the paper reported.

But the buyout firms had not been given access to Guaranty's confidential financial data heading into the weekend, according to the report.

Guaranty is the second-largest publicly traded bank in Texas, with about $16 billion in assets, according to its website.

Last month, the lender said there was substantial doubt that it can continue as a going concern after loan losses and write-downs left it short of capital.

A source told Reuters at the time the bank was in talks with at least one investor group for a recapitalization.

Representatives from Guaranty, JPMorgan, Toronto Dominion, Blackstone, Carlyle and Oak Hill Capital were not immediately available for comment. A TPG spokesman declined to comment.

(Reporting by Anupreeta Das; Editing by Richard Chang)