NEW YORK — The scandal over the manipulation of stock options grants spread to yet another executive as the former chief executive of Monster Worldwide Inc. quit his board seat at the job search Web site and refused to sit for questions from fellow directors about past accounting practices.

The company announced Andrew J. McKelvey's resignation yesterday. A board committee conducting an internal investigation into so-called "backdating" options had sought to interview McKelvey further after questioning him in July. Monster has received a subpoena from the U.S. attorney's office in the southern district of New York over the issue and has said it wants to complete its own investigation by year's end.

McKelvey, 71, is the latest executive to leave a position amid investigations into the accounting for past options grants. In all, at least 135 U.S. companies have disclosed internal inquiries or government investigations, and at least 39 executives and board directors at 19 companies have been fired or resigned.

McKelvey's full resignation from the board comes just weeks after he stepped down from the posts of chairman and chief executive. At that time, he retained a spot on the board and was named chairman emeritus.

Top executives who have resigned from other companies over options investigations include: UnitedHealth Group Inc. Chief Executive William McGuire, KLA-Tencor Corp. Chairman Kenneth Levy, CNET Networks Inc. Chief Executive Shelby Bonnie and McAfee Inc. CEO George Samenuk. McGuire quit as chairman this month and will resign as chief executive by Dec. 1.

So far, federal authorities have filed charges against former officials from two technology companies. Securities and Exchange Commission Chairman Christopher Cox said yesterday that he expected more such charges in the coming days.

McKelvey "doesn't want to answer questions because anything he says can be used against him in any criminal investigation," said Jerry Reisman, an attorney specializing in corporate fraud at the firm Reisman Peirez & Reisman.

Backdating involves issuing stock options retroactively to coincide with lower points in a company's share price. Doing so creates a lower exercise price to buy the stock, instantly giving the options award greater potential value for the recipients. Normally, options carry zero value on the date of issue.

Monster issued a statement yesterday disclosing that, through a lawyer, McKelvey declined to be interviewed by a special committee of the board in a meeting that had been set for yesterday. He also would not assure the board that he would appear at a later date.

A lawyer for McKelvey wrote in a letter that the former executive refused to meet because he did not have sufficient time to review the facts of what had happened over the course of several years. Attorney Steven Reich also argued that Mc-Kelvey did not know backdating was illegal when he answered questions at a July meeting.

"He did not understand that it was improper for the exercise price of stock to be different than the price on the grant dates, nor did he understand there were legal or accounting implications associated with that difference," Reich wrote.

Monster's ongoing internal investigation had also delayed the release of its latest quarterly earnings results and led to the suspension of Myron Olesnyckyj, the company's general counsel.

When McKelvey resigned as chief executive, he was replaced by William Pastore. Monster's board also created a three-person executive committee for board matters.

Shares of Monster Worldwide rose $1.03, or 2.56 percent, to $41.32 on the Nasdaq Stock Market.