With little doubt about the outcome, Delta Air Lines Inc. and Northwest Airlines Corp. prepared to make their case to shareholders on why they should approve a combination that would create the world's biggest carrier and swallow whole an 82-year-old company in the process.

Northwest shareholders were set to meet for what could be the last time today in New York to vote on whether to accept Delta's acquisition offer, while Delta shareholders were set to meet near Atlanta in the afternoon to vote on whether to issue stock to Northwest shareholders as part of the transaction. Northwest shareholders also were to conduct other routine business at their annual meeting.

Four shareholder advisory firms have recommended votes in favor of the combination. The International Association of Machinists and Aerospace Workers, which represents 12,500 Northwest ground workers, opposes the deal.

Majority votes are needed for the proposals to pass. Shareholder approval is highly likely.

That would leave U.S. regulatory approval and a pending federal lawsuit seeking to block the deal as the only remaining hurdles. A Justice Department decision could come in the next month or two. The lawsuit is set for trial Nov. 5 in San Francisco. Delta hopes to close the deal by the end of the year.

Northwest shareholders would get 1.25 shares of Delta stock for each share they own if the combination is completed. That values Northwest at roughly $2.8 billion, based on Delta's current stock price and the 277 million Northwest shares outstanding or still to be issued as part of its bankruptcy reorganization plan. That's about $800 million less than the value when the deal was announced April 14.

The combined airline would be called Delta and keep its Atlanta headquarters and its chief executive, Richard Anderson. Northwest would become a wholly owned subsidiary of Delta during the integration process. Delta hopes to obtain a single Federal Aviation Administration operating certificate in 15 to 18 months.

Delta Chairman Daniel Carp would become chairman of the new board of directors, and Northwest Chairman Roy Bostock would become vice chairman. The new board would be made up of 13 members — seven from Delta's board, five from Northwest's board, including Northwest CEO Doug Steenland, and one from the Air Line Pilots Association. A current Delta pilot would take the pilots' seat on the board.

If the deal is completed, Delta plans to issue a nearly 13.4 percent equity stake in the combined airline to employees. Delta's shareholders will be asked at their meeting today to amend the company's performance compensation plan to allow Delta to issue the equity to employees.

Delta has already reached an agreement with pilots of the two airlines on a joint contract, though a deal to integrate the seniority lists of the two pilot groups remains elusive. Arbitration hearings on the seniority issue are set to begin Oct. 2 in Los Angeles. The pilots are the only major union at Delta, while Northwest is heavily unionized.

A vote on union representation for flight attendants from both carriers is expected after the combination closes.

The IAM represents Northwest ramp workers and reservation and customer service clerks, and has been working to organize those same workers at Delta. They need the support of 35 percent of the workers at the combined carrier to trigger an election, which would be decided by a majority vote.

IAM spokesman Joseph Tiberi said the union doesn't "believe it's in the best interest of shareholders to approve a merger that's going to create a mega airline with tremendous debt and the enormous task of integrating two vastly different corporate cultures."

The new airline would be the biggest in the world in terms of traffic and biggest in the U.S. in terms of annual revenue, which was a combined $31.7 billion at the end of last year.