NEW YORK — Wachovia Corp., at the center of a fight between Wells Fargo & Co. and Citigroup Inc. over who will buy the beleaguered bank, said Sunday it is pressing ahead with its deal to sell itself to Wells Fargo.

Wachovia responded to a judge's order Saturday temporarily blocking the sale of the bank to Wells Fargo, saying it does not believe the order "has any effect on the validity of the Wells Fargo agreement with Wachovia."

New York State Supreme Court Justice Charles Ramos issued the order blocking the sale of Wachovia, which Wells Fargo had agreed to purchase in a $14.8 billion deal. Citigroup accused Wells Fargo of trying to cut off its earlier takeover offer of Wachovia's banking operations for $2.1 billion in a deal struck with the assistance of the Federal Deposit Insurance Corp. On Friday, four days after that deal was struck, Wells Fargo said it was buying all of Charlotte, N.C.-based Wachovia.

The FDIC said Friday that it "stands behind its previously announced agreement with Citigroup." It also said it would review all proposals and work with regulators of all three institutions to resolve the tug-of-war.

The government insurance agency held an auction for Wachovia after the bank was weakened by billions of dollars in write-downs from failed mortgages. It was a big originator of what are called option adjustable-rate mortgages, which offered very low introductory payments and let borrowers defer some interest payments until later years. Delinquencies and defaults on these types of mortgages have skyrocketed in recent months, causing big losses for the banks.

Wachovia spokeswoman Christy Phillips-Brown said in a statement the company believes its agreement with San Francisco-based Wells Fargo is "proper, valid and ... in the best interest of shareholders, employees and the American taxpayers."

She said Citigroup is free to make a better offer to Wachovia under that agreement.

In its request to Ramos, Citigroup invoked an exclusivity agreement in its agreement that bars Wachovia from talking with other potential buyers. In New York, the Supreme Court is a trial-level court; it was quite possible that ligitation among the three banks could go on for some time.

The legal fight pits two of the largest remaining financial institutions against one another as the ongoing credit crisis leads the federal government to arrange marriages and sales among banking entities.

Wells Fargo did not respond to messages seeking comment about the temporary order blocking the sale.

Wachovia is among the prominent U.S. financial institutions that have been jeopardized by the credit crisis that began with the housing slump and subsequent wave of mortgage defaults last year. It struck its deal with Citigroup shortly after Washington Mutual Inc., the nation's largest thrift and another big originator of option ARMs, was seized by the government; its banking assets were taken over by JPMorgan Chase & Co.