You can check off David Rehr from the unofficial K Street watch list of endangered GOP association heads. The Republican lobbyist, best known for his hard-charging approach, abruptly resigned his post Wednesday at the helm of the National Association of Broadcasters.

While some Democrats on and off Capitol Hill had long complained of Rehr’s partisan stripes, in the end it was more a matter of policy defeats than personality that led to his exit, industry sources said.

In early 2007, Rehr had made it the NAB’s mission to block the proposed merger between XM Satellite Radio and Sirius Satellite Radio. Despite his efforts, the merger went through.

More recently, Rehr’s industry has been playing defense to beat back Congressional proposals to force broadcast radio stations to pay record labels and performance artists royalties every time the stations play their songs.

The NAB’s lobbying spending during the first quarter was basically flat compared to the same time period last year, with the association doling out $2.6 million in lobbying spending, according to Senate records.

One industry source said Rehr’s take-no-prisoners approach, particularly on the long-simmering battle with the recording industry over performance royalties, did not sit well with the massive group’s members.

Rehr reportedly said he would rather slit his own throat than negotiate with the recording industry over the issue.

“It’s clear at this point that David’s absolutist approach against negotiating with the recording industry had the effect of slitting his own throat,— said one industry source familiar with the situation.

Under current law, record labels and recording artists do not receive royalties when over-the-air radio stations broadcast their songs. Internet and satellite radio stations do pay royalties.

The Democratic Congress is working on a bill that is set to be marked up next week that would give performance royalties to artists and labels.

The announcement comes less than three weeks after Rehr delivered the opening remarks at the annual NAB convention.

At the time, Rehr acknowledged that the industry was facing tumultuous times but gave no indication that he wouldn’t be at the helm of the organization.

Rehr, who previously headed the National Beer Wholesalers Association, had earned a reputation for being close with the GOP and former House Majority Leader Tom DeLay (R-Texas). That led some K Street Democrats to grumble when he got hired — and led to much speculation about the length of his tenure after the 2008 elections.

“There’s certainly a time where people say, Look, I see the writing on the wall,— one headhunter said of Rehr’s decision to leave.

In 2007, the last year for which such figures are available, Rehr’s salary was $758,750, according to the NAB’s publicly available tax return. That same year, membership dues accounted for about $10 million, with about $40 million in other revenue earned as well.

Rehr made several staffing changes to the NAB’s in-house lobbying lineup, bringing on Laurie Knight from the NBWA about two weeks after he joined the NAB. Knight, a former legislative aide to then-Rep. Jim Turner (D-Texas), is the NAB’s executive vice president of government relations and the group’s top Democrat.

It is unclear what additional changes might be on the horizon.

NAB Chief Operating and Financial Officer Janet McGregor will run the association until the NAB names Rehr’s replacement, according to NAB spokesman Dennis Wharton, who added that Rehr plans to remain with the NAB temporarily.

McGregor joined the NAB in October 2008 after serving as president and CEO of Lockheed Martin Investment Management Co. She began her career in 1979 in the treasurers’ organization of the Martin Marietta Corp., which later merged with Lockheed.

McGregor, who has not given extensive political contributions, most recently contributed $1,000 on Jan. 26 to then-Republican Sen. Arlen Specter’s (Pa.) campaign committee, according to Federal Election Commission records.