NEW YORK (AP) -- Aluminum manufacturing giant Alcoa Inc. reached a tentative agreement on a new contract with its largest union Tuesday, avoiding a possible strike that would have affected thousands of workers.

Details of the four-year agreement between Alcoa and the Steelworkers Union were not immediately available. It still must be ratified by union members in 10 states over the next few weeks.

"We have spent the last two weeks working through some tough issues, and feel that this tentative agreement crefor good paying jobs at these plants," Mick Wallis, president of Alcoa North American Rolled Products, said in a statement.

The contract was extended about half a day beyond its expiration at midnight Monday, as both sides continued to discuss terms.

Jim Robinson, director of USW District 7, said the agreement came down to the last minute but declined to identify any sticking points or to characterize how the talks went.

Union officials said they would not discuss specifics of the new n strike against Alcoa was in 1986.

The current contract covers about 5,400 employees at 10 facilities in Texas, Arkansas, Washington, Tennessee, Indiana, New York, Iowa, and North Carolina. Alcoa has about 59,000 employees in 31 countries.

Alcoa shares fell 21 cents to $11.43 in afternoon trading.