Local Republican Party leaders, after a long search for a candidate, have convinced a Democratic committeewoman to cross party lines and run for mayor.

Karen Brown, a retired Catholic-school teacher from South Philly, had already shown unusual political ambition this year by running as a Democrat for both a City Council district seat and an at-large seat.

If she can collect at least 1,000 signatures from registered Republicans on nominating petitions by Tuesday, Brown will face real-estate agent John Featherman in the May 17 primary election.

GOP chairman Vito Canuso and Michael Meehan, the party's general counsel, have not embraced Featherman's campaign because he is among the insurgents unhappy with how the party operates in the city.

Brown yesterday said Canuso and Meehan have been "courting me for some time" and noted that she has cordial relations with the Republican Party, even though she has been a Democrat since Jimmy Carter was president.

"They asked me to run," Brown said after meeting with Canuso and Meehan yesterday. "They think it's time for a woman. I agree with them."

Brown said she has been frustrated that the local Democratic Party has not been supportive of her twin campaigns for Council, after she spent years helping to elect other candidates.

"I'm a serious candidate," Brown declared yesterday, vowing to change her registration to Republican later in the day. "If the Democrats won't have me and the Republicans will, that's the way I'll make a difference."

Canuso confirmed that the GOP will circulate nominating petitions for Brown for mayor.

"She's very enthusiastic," Canuso said. "She's very experienced in campaigns. She was running two. Now she's running one."

Canuso said the party will call a meeting of ward leaders before the primary to consider endorsing a candidate. The options are to endorse Brown or Featherman or to have no endorsement.

Meehan has said it is "highly unlikely" the party will endorse Featherman, who entered the race for mayor in June.

Featherman said he met with Canuso and Meehan Tuesday and thought they might be moving closer to accepting his candidacy. Then Canuso called him yesterday to tell him Brown was getting into the race.

Several Republicans approached by party leaders this year have considered running for mayor but then have declined, prompting speculation that they wanted a clear path to the general election without what is anticipated to be a interparty tussle with Featherman in the primary.