Citigroup Inc said it won a court order late on Saturday blocking Wells Fargo & Co. from buying hobbled US bank Wachovia Corp until the court rules otherwise. Citigroup, which planned to buy Wachovia's banking assets for $2.2 billion, said New York State Supreme Court Justice Charles Ramos granted an injunction extending Wachovia's agreement to negotiate exclusively with Citigroup. The two banks are slated to appear before the judge on Friday Oct. 10. Citigroup and Wells Fargo are battling for control of sixth-largest US bank Wachovia, which has been hit hard by bad mortgages but has a large network of branches. The global credit crunch is forcing weaker banks to sell themselves, sometimes at the urging of the US government. Citigroup, the largest US bank, said on Monday it had preliminarily agreed to buy Wachovia's banking operations in a government-backed deal. That deal did not include a signed merger agreement, but Wachovia did sign an agreement to only negotiate with Citigroup through Monday October 6. On Friday, Wells Fargo said it had signed an agreement to buy the whole of Wachovia, including its asset management unit and retail brokerage, for about $15 billion. Some lawyers believe that Citigroup could have a real case, noting the exclusivity agreement.