April 8 (Reuters) - U.S. Steel said on Tuesday that activist investor Ancora

Holdings, who previously attempted to undermine the planned merger with Japan's Nippon Steel ( NISTF )

, has "flip-flopped" and now claims to be in support of the transaction.

In connection with the proposed deal, Ancora has recently unveiled a plan that could deliver

a cash offer of $75 per share. However, the investor, which owns less than a 1% stake in the

company, said that it has no intention of standing in the way of the $55 per share Nippon deal.

Pittsburgh-based U.S. Steel called Ancora's "last-minute plan" inconsistent and said, "If

Ancora now believes their plan would deliver $75+ per share, why are they suddenly also

supporting a $55 per share cash deal with Nippon Steel ( NISTF )?"

Separately, Ancora on Monday called on U.S. Steel's board to delay its annual stockholders

meeting until after June 18. Currently, the meeting is scheduled to take place on May 6.

The move comes after U.S. President Donald Trump directed the Committee on Foreign

Investment (CFIUS) to conduct and finalize a new review of the transaction within 45 days.

Ancora launched a boardroom challenge at U.S. Steel early this year and has nominated nine

candidates to the company's board of directors, as it looks to oust company CEO David Burritt.

U.S. Steel said in a statement on Tuesday that shareholders of the company should vote for

all 10 director nominees standing for election and "discard any materials sent by Ancora."

Ancora did not immediately respond to a Reuters request for comment late Tuesday.