What was expected to be Broadway’s first billion-dollar year is now set to become the scene of a walk-out. Hundreds of Broadway theatrical stagehands have threatened to refuse to work if they do not settle contract negotiations with the trade organization that represents top theaters in the city.

After two months of negotiations, the two parties — the union, Local One of the International Alliance of Theatrical State Employees, and the trade group, the League of American Theaters and Producers — each submitted what they said were final offers yesterday evening.

No agreement was met, and there are no further negotiation discussions currently scheduled.

The union, which represents as many as 500 stagehands in New York and includes skilled carpenters, electricians, and sound technicians, had been working without a contract since it expired at the end of July.

The League represents two New York theater owners, the Jujamcyn and the Shuberts, who account for 22 of the 39 Broadway theaters. The Nederlanders, who own nine theaters, had a separate contract with Local One. The Nederlanders’s contract expired, and they are now at the negotiating table as observers, union sources said. A walk-out would shut down all Broadway shows except “The Ritz,” “Pygmalion,” Mary Poppins,” and “Mauritius,” all of which are playing at nonleague theaters.

At the heart of the contract negotiations is a struggle over how to reflect the economic realities of staging a show on Broadway. Such shows are often exorbitantly expensive to produce and are rarely profitable, according to sources close to the talks.

The union and League are also at odds over whether stagehands should only be paid for the work they physically do, as the League argued, or if the theater should hire the same stagehands each day to do the same job, regardless of whether work is available.

The League released the details of its final offer, which included a 16% wage increase over five years plus a separate 10% wage increase for the period when shows are loaded in, and a new sick pay provision. The League has said the stagehands are among the highest paid union workers in the city, earning as much as $115,000 on average per year while working on a running musical.

While the details of the union’s final offer were not released, the League’s executive director, Charlotte St. Martin, said it made no progress on any of the crucial issues the League had identified.

“The League’s purpose is to modernize a contract,” Ms. St. Martin said in a statement. “It is a compromise that preserves many contract provisions Local One sought to protect, but at the same time liberalizes some archaic work rules.”

The president of Local One, James Claffey, Jr., said its final offer “offered imaginative solutions” that ultimately did not meet the producers’ requests.

“What the producers failed to do was recognize our suggestions with exchanges of its own,” Mr. Claffey said in a statement. “Local One is open to exchanges on work rules and other areas, but would not make a concessionary agreement of any kind. Local One will not accept cuts.”

Should the theaters go dark as the season picks up this fall, the union has an emergency defense fund reported to be over $4 million.

The theaters have a reported $20 million warchest, but paying costs for shows not performing could quickly eat at that money, union sources said.

In 2006, the League announced Broadway box offices grosses of nearly $940 million. Income data from licensing, secondary rights, film rights, and merchandise sales is not publicly available.