Ervin Duggan has resigned as president and CEO of the Public Broadcasting Service.

Officially, PBS says that Duggan announced his resignation yesterday because he's achieved all that he set out to do there, and he's moving on to look for new challenges.

But sources close to the situation say that public TV stations spat him out after a somewhat contentious five-year relationship.

"It was like a low-grade fever--eventually you just take a mega-aspirin and get rid of it," said one public television source.

There is no one reason for Duggan's departure, say these sources, who in keeping with the general close-mouthed policy that is public television declined to be named. However, some of them pointed to the abrupt and unexpected exit of PBS chief operating officer Bob Ottenhoff, a man well liked by station honchos, as having likely helped turn the tide against Duggan. Ottenhoff's removal came just before the PBS annual meeting in June, in San Francisco--an event at which he was often a key speaker.

At the time, the publication Current, which is administered by PBS member station WNET in New York, reported that Duggan's announcement of Ottenhoff's departure at the June 6 opening session "mystified station executives and even some PBS board members."

Duggan spent more than five years in his like-hate relationship with the PBS member stations. His personality, described by one source as "articulately arrogant," made him some enemies. And his determination to make Alexandria-based PBS more "entrepreneurial" often put him at cross-purposes with the powerful producing stations, including WNET, Washington's WETA, WGBH in Boston and Los Angeles' KCET.

Back in '98, WETA chief executive Sharon Percy Rockefeller expressed concern about an "inherent structural conflict" between PBS and its stations as Duggan worked to transform it from a renter and distributor of programming produced by larger PBS stations to a financier and producer itself. Since this role has traditionally been played by those big-city stations, it put PBS in direct competition with them for air time, production talent, show concepts and money. Station execs did not like to find out that PBS representatives were trying to cut deals with producers with whom the stations had decade-long relationships.

Rockefeller could not be reached for comment yesterday. But her office released a statement in which she praised Duggan as "an articulate champion for public television" and then went on to say that as a member of the search committee, she will work to find a chief executive for PBS who "has the vision and skills to work with stations to compete in today's dynamic telecommunications environment."

PBS board member John F. Swope will serve as interim chief executive when Duggan leaves Oct. 31.

Duggan said in yesterday's announcement that he had fulfilled his objectives: "A strategy to create greater financial security and enduring value for PBS and its member stations is now in place."

Under Duggan, PBS increased revenues 70 percent--from $182 million in 1995 to a projected $309 million in 2000. The organization also expanded into new ventures, including the recently launched PBS Kids channel.

"PBS has been significantly strengthened under Ervin Duggan's leadership," PBS Board Chairman Colin G. Campbell said in the same news release. "His efforts have earned the appreciation of our colleagues in public broadcasting and of a citizenry that recognizes and depends on the excellence he has championed."

Duggan's resignation came the same day that the Corporation for Public Broadcasting's inspector general's office put out the final version of its report on the political donor-list flap.

The report found "no evidence that public broadcasting stations intended to benefit any political organization" by trading donor lists, CPB President and CEO Robert T. Coonrod said in a statement yesterday. The inspector general also reported that the exchanges occurred at 9 percent of the stations "and were therefore not a widespread practice," Coonrod said.

Though PBS did not come under fire for the list swapping, Duggan and other PBS officers were called before the House telecommunications subcommittee to explain why 30 stations--including WGBH, WNET and WETA--shared their membership lists with political groups. Some of the public TV stations involved had said that the swaps were a nonpartisan fund-raising tool, but conservative critics blasted the practice as further evidence of public broadcasting's liberal bias.

The office of Rep W.J. "Billy" Tauzin (R-La.), who chairs that subcommittee, suggested yesterday that the public TV stations had set up Duggan to take the rap for that embarrassment. Since the story broke, Tauzin's been talking about cutting the federal subsidy for public broadcasting.

"Do we find a connection? Of course we do," said Tauzin aide Ken Johnson. "The inference is he is being forced to walk the plank for the donor-list scandal. He's no more to blame for this than I am."

"PBS and CPB are telling us that there's no connection between the [Duggan] announcement and the release of the report," Johnson said. "Why do it today then? This story [on the report] was destined to be buried on the inside of most newspapers. All of a sudden it's Page 1 because Duggan's resignation is announced on the same day. It makes it look like they're saying, 'We have identified the problem, we have solved the problem, and now we're moving on.'

"Ervin Duggan wasn't the problem. The problem was questionable leadership at the station level in markets all across the country."

A PBS spokesman, however, insisted that the timing was coincidental.

Duggan's resignation came the morning after PBS took home the most trophies of any network at the 20th annual News and Documentary Emmy Awards.

The public broadcasters earned 10 statuettes, including three for the series "The Living Edens" and one to "The NewsHour With Jim Lehrer." CBS followed, with six wins, while ABC and NBC got five each.

National Geographic Television was a big winner, taking home seven Emmys, including best coverage of a breaking news story for the TBS program "Saving JJ" and best informational or cultural programming for TBS's "Realm of the Great White Bear."

The ceremony, held Wednesday night in New York City, was a night of firsts.

Spanish-language network Univision won its first Emmys--two of them--for its coverage of Hurricane Mitch in Central America.

That's one more win than went to CNN at the Wednesday night ceremony. The cable news network snared just one win. And that was Larry King's very first News Emmy, which he picked up for his interview with death row inmate Karla Faye Tucker--her last before her execution--on "Larry King Live." King has been doing his show for CNN for 15 years. And Animal Planet nabbed its first Emmy, for its Dick Cavett-narrated series "Twisted Tales," which got a nod for writing. Sister channel Discovery also scored one win, for "Spytek."

One of the more timely trophy handouts was among HBO's cache of four, for "Waco: The Rules of Engagement." The film was among several programs honored for investigative journalism. It had been nominated for an Academy Award for best documentary feature in 1998; it aired on HBO earlier this year.

The prizes for work done during 1998 were awarded by the National Academy of Television Arts and Sciences.

A complete list of the News and Documentary Emmys appears on The Post's Web site, washingtonpost.com

CAPTION: Ervin Duggan may have rubbed some people the wrong way during his five years at the PBS helm.