Is the curtain going up on a Broadway labor showdown?

Negotiations between the League of American Theatres and Producers reached a critical stage Tuesday as the producers presented what they said was the League's final offer to Local One, the Broadway stagehands' union.

"The League seeks a contract that requires that we only pay for work we actually need and is actually performed," said Charlotte St. Martin, the league's executive director.

The offer includes a 16 percent wage increase over five years, a separate 10 percent wage increase for the period when shows are loaded in, an additional increase for the lowest paid stagehands, as well as a new sick pay provision, St. Martin said.

"The union is working very hard on its `last best offer' and hope the producers accept it," said Bruce Cohen, a spokesman for Local One of the International Alliance of Stage Employees, which represents Broadway's carpenters, electricians, props workers and sound technicians.

What happens next is up in the air. If an agreement is not reached, the producers could decide to lock out the stagehands, effectively shutting down most theaters. Or the two sides could continue talking, which they have been doing intensely over the last month.

A shutdown would affect most commercial Broadway productions but not those produced by such nonprofit organizations as the Roundabout Theatre Company, Manhattan Theatre Club and Lincoln Center Theater. Also apparently not affected are shows in theaters owned by non-League members, which include the Hilton, where Mel Brooks' "Young Frankenstein" begins previews Thursday, and the Disney-owned New Amsterdam, home to "Mary Poppins."

If Broadway shuts down, it would be the first time since 2003, when more than a dozen Broadway shows went dark after Local 802 of the musicians union held a four-day strike.

The stagehands have been working without a contract since July. The thorniest issue dominating the negotiations are rules governing "load-ins" — putting a show's physical production into a theater.

Producers say the rules are cumbersome and expensive and that they need more leeway to determine how and how many stagehands are needed. League members, who include theater owners, producers and general managers, have reportedly put together a $20 million fund to help some of the less popular shows financially weather a possible shutdown.

St. Martin said Tuesday's offer by the League is "a compromise that preserves many contract provisions Local One sought to protect, but at the same time liberalizes some archaic work rules so that they begin to reflect those present in most modern workplaces."

The 3,000-member union, which has between 350 and 500 members working on Broadway at any given time, contends it could find employment for many of its people in television or film if a work stoppage occurs.