The union representing 2,400 Port Authority bus-trolley operators, mechanics and other personnel is asking for a four-day work week based on 10-hour days, improved health care and higher pensions and wages.

On the other hand, authority management wants to raise the retirement age to 60, eliminate post-retirement health care coverage, increase employee pension and insurance contributions, and pay new hires at wages 20 percent below others.

The bargaining positions are more divergent than at any time in the past and have precipitated the most contentious labor negotiations in the 44-year history of the transit agency. Negotiations began April 29.

Patrick McMahon, president-business agent of Local 85, Amalgamated Transit Union, said yesterday that talks so far have seen little progress. He said a strike is "a real possibility" if the authority persists in eliminating health care for retirees and other gains achieved through collective bargaining over the years.

He accused Allegheny County Chief Executive Dan Onorato of "calling the shots" and "giving marching orders" to authority negotiators.

"We're thinking of filing unfair labor charges against him," Mr. McMahon said, claiming Mr. Onorato has "backed himself into a box" by insisting upon contract cuts to help justify his support for a controversial 10 percent drink tax and $2-a-day car rental tax to subsidize transit.

The contract with Local 85 expires at 12:01 a.m. July 1. However, any strike likely would not take place before fall because state law sets forth a series of procedures once the contract expires, including state-supervised mediation and fact-finding.

Authority Chief Executive Officer Steve Bland said while he keeps in touch with Mr. Onorato and his staff about various transit matters, Mr. Onorato "is not involved in current labor negotiations in any way, shape or form."

But he said Mr. Onorato has told the authority to achieve a contract that results in "an affordable, sustainable mass transit system where we don't have to raise fares and cut service every year."

Mr. Onorato expects a contract to be worked out, said his spokesman, Kevin Evanto.

"The county executive said he expects Mr. Bland and authority management and Mr. McMahon and his leadership team to go into a room, get a competitive contract done and quit trying to draw him into this," Mr. Evanto said.

Mr. Bland said union members need to realize that the transit agency is engaged in a financial life struggle.

"It does employees no good to have the richest contract in the transit industry if we can't save their jobs and provide the level of service that Pittsburgh and Allegheny County need," he said.

For the 2008-09 fiscal year that begins July 1, fringe benefits for the entire 2,715-member Port Authority work force are projected to cost $111.6 million, and wages $137.5 million. Soon, Mr. Bland said, benefits will cost more than wages if the authority is unable to bring costs under control. The number of retirees exceeds the number of active employees.

"Riders have given fare increases and service cuts, the public has given the drink tax and car rental tax, and nonrepresented employees have given up benefits, so the union is the last of the Mohicans," he said. "It's not a question of the union deserving benefits, it's just that we can no longer afford all of them."

While the authority's contract proposal does not offer a pay raise, it doesn't preclude one, apparently depending on the outcome of bargaining on the bigger health care and pension issues.

Mr. McMahon said Local 85 members expect to keep up with inflation that has risen beyond the 3 percent pay increases they received under the current three-year contract.

As for a four-day work week, he said negotiators discussed experimenting with it the last time on a trial basis at one of the five division bus garages.

"To be honest," Mr. McMahon said later yesterday, "the four-day week is not a deal-breaker. They're wages, pensions and health care. If we got those things, that's secondary."

Attorney Joseph J. Pass, Local 85's longtime labor counsel, added, "None of the problems is insurmountable."

The authority board has eliminated medical, dental, prescription and eye-care insurance coverage for nonrepresented employees and transit police union members retiring after last July 1. Those still working have lost other benefits and, as of this July 1, will be paying 13.5 percent toward health care premiums.

"Armageddon didn't hit when management underwent changes," Mr. Bland said.

Although Mr. Onorato has characterized the authority's benefits as outrageous, he's not the only critic of Local 85's contract.

Less than two years ago, a special Transportation Funding and Reform Commission appointed by Gov. Ed Rendell recommended that the Port Authority get its benefits and collective bargaining agreement more in line with other transit agencies across the state, including the Philadelphia-based Southeastern Pennsylvania Transportation Authority.

Last October, the Pennsylvania Economy League of Southwestern Pennsylvania said authority wages, when adjusted for inflation, were the highest of any transit system in the nation. It also pointed out that SEPTA is spending $7.3 million on retiree health care this year while the Port Authority is spending $29.2 million, although the latter is only one-third as large.