Four unions have signed a new labor agreement with the Pennsylvania Convention Center.

A spokesman for the Convention Center said this morning that the riggers, electricians, stagehands and laborers unions signed the "customer satisfaction agreement."

The center's board then approved the agreement at a morning meeting, according to spokesman Pete Peterson.

The labor groups that signed the deal agreed to new rules that will allow exhibitors to do more of their own work, instead of using union workers.

Center officials had given the unions a midnight deadline to sign on. Two unions, the teamsters and carpenters, had not signed the agreement as of this morning.

The United Brotherhood of Carpenters Local 8 picketed outside the center last week in protest of the new rules.