Striking pilots at Northwest Airlines approved a new four-year contract with the carrier on Saturday, officially ending a bitter two-week strike against the nation's fourth-largest carrier in an action that has disrupted travel in much of the Midwest and the South.

After meeting all day at a hotel in Minneapolis, where Northwest is based, the governing Master Executive Council of the Air Line Pilots Association, which represents Northwest's 6,200 pilots, ratified the tentative agreement that was reached on Thursday after two days of marathon negotiations mediated by a top White House aide."Now, we're ready to return to work and are looking forward to being back in the cockpit instead of on the picket lines," said Steve Zoller, the council's chairman. He also thanked President Clinton.

Northwest said that it planned to resume flying on Wednesday with about a quarter of its schedule and would have all 1,700 of its daily flights back in the air by the following Monday.

"We feel very confident that we will be able to meet our targets," said Donald J. Foley, a spokesman for the airline.

Acceptance of the agreement by the pilots ends the longest strike against an airline since machinists walked out at Eastern Airlines in 1989. The pilots and Northwest had been negotiating for two years before the 6,200 pilots walked out on Aug. 29. The two sides made virtually no progress toward a settlement until Bruce Lindsey, one of Clinton's most trusted aides, joined the negotiations on Wednesday.

For many in Washington, it might have been surprising that Lindsey would take a seat at the bargaining table in Minneapolis when a growing political crisis was engulfing Clinton's Presidency. But it seemed only fitting to officials at Northwest and the pilots union because the White house had loomed large in the calculations of both sides even before the strike began.

The tentative agreement, details of which were disclosed late Friday, includes a 12 percent raise over four years, a lump sum of $57 million to make up for lost wages, profit sharing and 2.5 million stock options for the pilots, and the phasing out of a two-tier wage scale that paid pilots a lower salary in their first five years.