Pittsburgh's police union took political aim at Mayor Luke Ravenstahl yesterday, endorsing his Republican challenger Mark DeSantis in an unusual gamble aimed at getting more equipment, a secure pension fund, and the right to live outside of the city.

Also yesterday, a representative of the city firefighters union, which has been active in past mayoral campaigns, said it would not endorse a candidate in the Nov. 6 election.

"We were looking for the most competent person, the most mature person, to do the job for us," said Fraternal Order of Police President Jim Malloy, speaking for some 850 active officers and 1,150 retirees. "And that's why we selected Mr. DeSantis."

Mr. Ravenstahl said the endorsement, sealed after a Thursday evening interview and a vote by the union's three-member political committee, was driven largely by the union's desire to break the city's longtime residency requirement for all employees.

"It was clear last evening that there were issues that I didn't agree with the union on, particularly the residency requirement," the mayor said. "I firmly believe that if employees are employed by the city of Pittsburgh, they should live in the city, whether that's a police officer, a fireman, a mayor, a nonunion official. I fundamentally believe in that."

The FOP made the first major union endorsement announcement of the mayoral campaign. It is unusual because union endorsements skew toward Democrats and incumbents, and Mr. Ravenstahl is both, as well as the favorite in a city where Republicans are decidedly outnumbered.

Union officials said their choice had nothing to do with any specific misstep Mr. Ravenstahl has made, nor with the debate over Police Bureau policies on officers who are accused of domestic abuse.

Mr. DeSantis "has business savvy. We see a lot of the same things in him that we saw in [late mayor] Bob O'Connor," said union Recording Secretary Chuck Hanlon, a member of the union's political committee along with Detective Frank Rende and union trustee Tom Leheny. All three voted for the Republican.

Union officials touted Mr. DeSantis' plan to use gambling revenue and donations from nonprofit groups to boost the city's troubled pension fund. They said they have been stymied in efforts to persuade Mr. Ravenstahl to spend money slated for new police cars, and have won a pledge from Mr. DeSantis to get them what the challenger called "the best possible equipment."

"The rest of city government is going to have to do more with less," said Mr. DeSantis, who has promised to cut overall city spending.

Mr. Malloy also confirmed that Mr. Ravenstahl has fought their effort to get legislation through the General Assembly that would allow them to bargain for the right to move outside of the city, while Mr. DeSantis supports them.

"Police officers and any city worker can live anywhere they want," said Mr. DeSantis, explaining his position on residency requirements. He said the city should be able to hire the best available job candidates, no matter where they lived.

Mr. Ravenstahl characterized the endorsement as the result of his unwillingness to kowtow to unions, making reference to Mayor Tom Murphy's May 2001 contract stipulations with the firefighters union that led to an endorsement, a ballooning Fire Bureau budget, and later a federal investigation.

"I'm not going to sell the taxpayers of the city down the river for a union endorsement like mayors in the past have right before elections," Mr. Ravenstahl said. "I make decisions based on the best interest of the residents."

The FOP's contract with the city expires at the end of 2009, which means the winner will have to negotiate a new pact. Numerous other city labor contracts end during the two-year remnant of the term won by Mr. O'Connor in 2005.

The Fraternal Association of Professional Paramedics is endorsing Mr. Ravenstahl, said President Jeff Vesci.

Mr. Ravenstahl said he expected that the firefighters union would not endorse a candidate. In 2005, the union endorsed Republican Joe Weinroth for mayor against Mr. O'Connor.

The mayor said he did not view the police union's endorsement as a setback for his campaign. "I believe the rank and file, the men and women in the police department, understand what we are doing and -- although this three-person panel may have chosen to go in a different direction -- will largely be supportive on Election Day."

Mr. DeSantis argued that it was a symbol of the dissatisfaction of many residents, even some who work for the mayor. "The people of Pittsburgh have had enough, and they want change, and they want it now."