Delta Air Lines (DAL) pilots handed the struggling airline a huge victory Thursday in its effort to avoid bankruptcy, agreeing to slash their salaries by more than $1 billion and receive no pay raises through 2009.

The pilot's union announced results of a 10-day vote by the Atlanta-based airline's 7,000 pilots, who approved the plan with 79 percent of the vote.

Union leaders reached a tentative agreement with Delta after 15 months of negotiations. The five-year contract calls for a 32.5 percent pay cut and becomes effective Dec. 1.

In return, the pilots get options to buy up to 15 percent of the company's stock.

Delta pilots are currently among the highest-paid in the nation with salaries averaging between $100,000 and $300,000 a year.

About 91 percent of eligible pilots cast ballots by phone and the Internet over the past 10 days. A simple majority was needed to ratify the agreement. The voting ended at noon Thursday.

News of the contract's ratification sent shares of Delta Air Lines Inc. surging more than 8 percent, or 51 cents, in late trading. The shares ended the regular session 21 cents higher, at $6.29, on the New York Stock Exchange (search).

Delta has lost more than $6 billion since early 2001, during which time it has eliminated 16,000 jobs and cut the pay of other employees, including its executives. Last month, the airline reported a $651 million loss in the third-quarter.

The company said it needed the wage concessions to stay afloat. But company officials have warned that the agreement still may not be enough to avoid bankruptcy.

Delta also must convince the holders of its $20.6 billion in debt to restructure the repayment terms for all the pieces of its transformation puzzle to fall into place.