In a bombshell shake-up at the WB Network, CEO Jordan Levin has resigned from the net he helped create as he rose through the programming ranks during the past decade.

WB chairman Garth Ancier will take on sole responsibility for running the network but will not assume the CEO title, WB executives said Monday. Ancier on Tuesday appointed producer and former Warner Bros. Television executive David Janollari as entertainment president, the job Levin held until his promotion to CEO in September.

Levin's resignation caught the industry by surprise Monday morning, but the shake-up at the WB had been in the works since the departure of founding WB chairman and CEO Jamie Kellner at the end of last month. Warner Bros. chairman and CEO Barry Meyer, who oversees the WB Network, decided that the network would be better served by having a single leader, and that Ancier should get the nod.

During the weekend, Meyer offered Levin the chance to stay on as WB Network entertainment president, but Levin rejected that and is now considering setting up a producing deal with the network's sibling studio, Warner Bros. Television. Levin stressed that he would seek a new job that involved both creative and business responsibilities.

"I'm not afraid of risk and not afraid of change, and I think that the television world is undergoing a real transformative change and there's some engaging opportunities for people willing to try and carve out new businesses," Levin said. "I did not (accept the entertainment president job) because of ego but because I've done that before and I really enjoyed being involved in marketing and sales and combining and melding the business and the creative together."

Levin had been promoted to the CEO post in September in preparation for Kellner's departure. At the time of Levin's promotion, WB, Fox and NBC veteran Ancier was brought back to the WB fold as chairman to share Kellner's former duties with Levin.

While Ancier and Levin had a long and close working relationship, sources said Meyer often found himself being called in to make final decisions on issues when the two WB chiefs disagreed. Sources said there was also concern that the bifurcated management structure would encourage factions within the WB staff.

Ultimately, sources said Meyer decided to make the streamlining quick to avoid any tensions going into the new season, where the WB is under pressure to rebound after showing some weakness in 2003-04.

"Taking the nontraditional organizational route was a noble effort, but having a sole leader is simply more productive, efficient and effective," Meyer said in a statement. "Garth and Jordan are both extraordinarily talented executives and superstars in their own right. We are delighted that Jordan will become an independent producer for WBTV. Once cannot overstate Jordan's contribution to the success of the WB, and we look forward to him duplicating that success at WBTV."

Both Ancier and Levin, whose working relationship goes back 15 years to when Levin was a trainee in the Walt Disney Co.'s television division under then-head Ancier, said they felt comfortable with the two-man leadership structure.

"It has not been a difficult structure to work with, and I was perfectly happy to keep going this way," Ancier said.

Levin acknowledged that Meyer has the right to put his stamp on the management of the WB.

"There's been a degree of a desire clearly expressed on Barry's part to have a management structure that is clean in its reporting, but that's not the way the WB has operated in large part," he said. "Even if there's been a clean report line, it's always been a kitchen cabinet of sorts, and I think that worked very well under Jamie's management."

For sure, however, Monday was a tough day for both Ancier and Jordan as well as many WB staffers.

"It's been a very emotional day for me because of the outpouring of support that I've gotten and, in some ways, it's been a really special day," Levin said, his voice cracking at times. "You don't get often an opportunity to see how much you have impacted people."

One of those impacted by Levin is Greg Berlanti, creator and executive producer of the WB's hit "Everwood" and exec producer of the upcoming WB drama "Jack & Bobby."

"I'm utterly shocked; it's been an extremely emotional day," Berlanti said. "He gave me my first and biggest break in the business by getting me to run 'Dawson's (Creek),' and then he bought 'Everwood' when no one else wanted to touch it because it was a year where everybody was only buying procedurals. There's no way I'd be running TV shows right now if it weren't for Jordan, and I've had no greater friend and advocate in the business. I'm going to figure out a way to work with him as closely as possible and as soon as possible."

Said Aaron Spelling, executive producer of the WB dramas "7th Heaven," "Charmed" and newcomer "Summerland": "I adore Jordan as a human being. I'll miss working with him. He knows that I hated to fly, and whenever we'd talk about him taking a trip, he'd always call me whenever he landed to tell me he was safe. That's the kind of guy he is."

Levin, who early this year inked a new multiyear contract with the WB, also was offered a producing deal with WBTV. He said he is leaning toward accepting the offer and segueing into producing, at least short-term, "to exercise my creativity at this time," but he made it clear that his long-term goal is to return to the executive ranks.

Observers traced the origins of Monday's WB shake-up back to February 2003, when Kellner exited his post as chairman of Turner Broadcasting System. When Kellner was tapped to head the Turner cable networks in early 2001, corporate oversight of the WB Network shifted from Warner Bros. to TBS along with Kellner. When Kellner prepared to depart TBS two years later, sources said he personally promised Levin that he would be promoted to CEO.

But once the WB returned to Meyer's portfolio at Warner Bros. after Kellner's departure from TBS, Meyer is said to have been uncertain about whether Levin was up to the task and thus pushed to bring Ancier (who had been working with Kellner at TBS) back in the chairman's role.

After giving the Ancier-Levin management structure a try this season, sources said it gradually became clear to Meyer and Bruce Rosenblum, who oversees day-to-day WB Network activities in his capacity as Warner Bros. Television Group executive vp, that a change had to be made.

Ancier, whose resume includes stints as head of programming at Fox and NBC as well as the WB, got the nod in light of his broader experience, sources said.

Levin was the third executive hired at the WB during its prelaunch phase in mid-1994, as head of comedy programming. He was promoted to co-entertainment president in 2001 and took full control of the entertainment division a few months later.

The door at the WB will stay open for Levin in his new capacity as an on-the-lot producer, Ancier said.

"I'd love him to produce for us," he said.