Pennsylvania's governor and Philadelphia's mayor announced Saturday that the city transit system's largest union had agreed not to go on strike as contract talks continued hours before the start of Game 3 of the World Series.

Gov. Ed Rendell and Mayor Michael Nutter told reporters told reporters late Saturday afternoon that a 6 p.m. strike deadline would pass with no walkout by the union representing more than 5,000 bus drivers, subway and trolley operators and mechanics of the Southeastern Pennsylvania Transportation Authority.

Rendell said there had been "substantial progress," and that although no agreement had yet been reached, he hoped one could be concluded quickly.

"We expect a contract very soon," agreed Willie Brown, president of the Transport Workers Union Local 234.

Nutter said union and transit system negotiators would stay at the table until a new contract is reached, and a walkout was "off the table."

"The system is up and running," he said. "Use it, today, tomorrow, the next day and the day after that while we're in the midst of this negotiation."

The union — which represents more than 5,000 bus drivers, subway and trolley operators and mechanics — had threatened to strike just after midnight Friday if there was no accord, but agreed to Rendell's request to keep talking on Saturday. The last contract expired last spring and members voted Oct. 25 to authorize a strike.

The Philadelphia Phillies and New York Yankees are scheduled to play the third, fourth and fifth games of the Series on Saturday, Sunday and Monday in Philadelphia. Most of the system's 810,000 riders use buses, subway lines and trolleys to get to work, but SEPTA spokesman Richard Maloney said about 8,000 people typically take transit to the baseball stadium for games.

Union workers, who earn an average $52,000 a year, are seeking an annual 4 percent wage hike and want to keep the current 1 percent contribution they make toward the cost of their health care coverage. SEPTA is offering no raises in the first two years and 2 percent raises in the final two years of a four-year contract and wants to raise the health care contribution to 4 percent.

A 2005 SEPTA strike lasted seven days, while a 1998 strike hampered the transit system for 40 days.