Tata Group has been forced to wait longer to know the outcome of its bid to acquire Corus, which today deferred the December 4 EGM by over a fortnight to enable rival suitor CSN make a formal offer.The shareholders of the Anglo-Dutch steel company would now meet on December 20 to vote on Tata Steel's 455 pence per share offer."The Board of Corus has decided it is in the best interests of Corus shareholders to allow CSN some additional time to satisfy its pre-conditions and to determine whether it will put forward a formal offer," the UK-based steel maker said in a release issued to the London Stock Exchange today.CSN was quick to welcome the move as "prudent," but Tata Steel officials preferred not to comment.A CSN spokesperson said: "the due diligence is still underway... (and it) would complete the due diligence process as quickly as possible." CSN had approached Corus Board on November 17, with a proposal of 475 pence per share in cash and is now studying the books of Corus ahead of launching a formal bid.On the other hand, Tata Steel's 455 pence a share bid last month has already been recommended by the Corus board."Since the CSN announcement, Corus has made due diligence information available to CSN and has also made senior management available to expedite this process with a view to enabling CSN to satisfy its pre-conditions as quickly as possible. However, to date, no formal offer has been received from or announced by CSN," Corus said."In light of this, the board intends to propose resolutions to shareholders at each of the EGM and the meeting convened for 4 December 2006 to adjourn those meetings until 20 December 2006," it said.