UPDATE 1-H&R Block CFO resigns

(New throughout, adds dateline)

NEW YORK, Nov 5 (Reuters) - H&R Block Inc (HRB.N), the largest U.S. tax preparer, on Monday said Chief Financial Officer William Trubeck has stepped down, effective immediately.

Treasurer Becky Shulman was named acting CFO, the company said. Trubeck will remain as a consultant through December. He joined H&R Block as CFO in October 2004.

The departure comes in what Trubeck called in a statement a "very challenging period," one marked by mounting subprime losses in the company's Option One Mortgage Corp unit.

H&R Block is trying to salvage at least part of an agreement to sell Option One to private equity firm Cerberus Capital Management LP [CBS.UL].

It had agreed in April to sell Option One for an amount estimated at perhaps $1 billion. That agreement collapsed as losses mounted from riskier home loans.

H&R Block lost $736.2 million in the 15 months ended July 31. Its Block Financial Corp unit has drawn down from its bank credit lines at least four times since mid-August.

Option One is based in Irvine, California, and H&R Block in Kansas City, Missouri.

H&R Block shares were down 58 cents to $20.01 in late afternoon trading. They began the year at $23.04. (Reporting by Jonathan Stempel, Additional reporting by Ankur Relia in Bangalore, editing by Gerald E. McCormick)