When City Council reached a compromise Monday with construction unions on minority hiring for the $700 million Convention Center expansion project, four of the 15 unions were not part of the deal. Yesterday, this question remained unanswered: Would those four be forced to comply with the agreement or would they be allowed to slide?

"It would be a disservice to the unions that complied not to ask the other unions to comply," said Patrick Gillespie, business manager of the Philadelphia Building and Construction Trades Council.

The four unions, however, represent more than 24,000 active and retired carpenters, electricians, operating engineers and roofers and are among the most politically influential associations in the region.

The Convention Center Authority has said any union not complying with Council's demands would not be allowed to sign the project labor agreement, which sets out work rules between the center and unions and contractors.

But as of yesterday, neither the Governor's Office nor the authority would say what that meant. "I have no idea what the consequences might be," said Gov. Rendell's spokesman, Chuck Ardo. That will be part of a review of Council's action, he said.

Councilwoman Donna Reed Miller, who led negotiations with the unions, could not be reached for comment.

Councilman W. Wilson Goode Jr. said yesterday that the authority's position "should be that they can't work on the project."

Mayor Nutter's spokesman, Doug Oliver, said it would be up to the state and Convention Center Authority to decide.

"For our part, we'll continue to ask that all unions comply," Oliver said. "Whether they do or not and what subsequently happens will, again, be determined by the Convention Center and the state."

Part of the agreement reached Monday calls for a mayoral Advisory Commission on Construction Industry Diversity to oversee the development of long-term plans for minority inclusion in the trades.

Anthony Wigglesworth, who mediated discussions among the unions, Council and the authority, said two of the four unions - the United Union of Roofers, Waterproofers and Allied Workers Local 30 and the International Union of Operating Engineers Local 542 - were expected to comply.

But the carpenters and electricians are another story.

Headed by Edward J. Coryell Sr., the Metropolitan Regional Council of the United Brotherhood of Carpenters and Joiners of America has always stood apart from the other building-trade unions.

"They dance to their own drumbeat," said Patrick J. Eiding, who heads the Philadelphia AFL-CIO, an umbrella group. "They are not part of my council and they could be, if they want to be."

Last year, the carpenters union had 12,762 members, including 9,289 who are active, making it one of the largest unions in Philadelphia. Counted among its members is U.S. Rep. Bob Brady, who chairs the city Democratic Party. According to the latest campaign finance reports filed Jan. 31, its political action committee had $1.4 million on hand. In 2006 and 2007, it donated at least $47,000 to Council members and candidates. Coryell has not returned repeated phone calls on the issue.

International Brotherhood of Electrical Workers Local 98 also has been generous to politicians. As of Jan. 31, Local 98's political action committee had $2 million in the bank. The local last year also donated thousands of dollars to at least nine Council members and candidates.

Local 98's business manager, John J. Dougherty, shrugged Monday when told he might be excluded from the project labor agreement. Dougherty flatly said he would not cooperate with Council but would work with the mayor's commission on diversity. "I don't get paid by City Council," Dougherty said, "I get paid by Local 98."