David Rehr resigned suddenly from the NAB where he has been president and CEO for the past three-and-a-half years. The 50-year-old chief lobbyist for America's broadcasters will stay on with the organization for the next several weeks or months while a search for a replacement is conducted.

NAB's chief operating and financial officer, Janet McGregor, will step up to work with Rehr to handle day-to-day matters from the massive association, sources close to the situation tell Billboard.biz.

Rehr's sudden resignation comes less than three weeks after the NAB held its major event of the year, the annual spring convention in Las Vegas, which in good times, generates nearly $50 million in revenue for NAB. This year's attendance was dramatically lower than in previous years, just under 84,000, the decline blamed on the recession.

However, under Rehr's leadership, the NAB has lost several significant battles, the most obvious the group's expensive attempt to stop the Sirius-XM merger. Both the Department of Justice, and then the FCC, approved the merger with inconsequential stipulations.

Rehr's 'take no prisoners approach' has caused the group great public discomfort. Last June during a panel session on performance royalties at The Conclave in Minneapolis, Rehr was asked if he would discuss a workable fee schedule with record labels. He responded with certain exuberance: "I'd rather slit my throat than negotiate," he said, stunning fellow panelists.

Rehr, who came to the NAB on Dec. 5, 2005 after serving as president of the National Beer Wholesalers Association, replaced Edward O. Fritts, who had been NAB president and CEO for 22 years. Fritts, who was well-regarded by politicians in both parties on Capitol Hill, was pushed out by a board of directors looking for a change.

Fritts left the NAB with a reported $7 million in various severance and retirement packages and now heads The Fritts Group, a D.C.-based lobbying operation that represents Fortune 500 companies on Capitol Hill.