New York  - The shareholders of Northwest Airlines and Delta Air Lines on Thursday overwhelmingly approved the planned merger of both companies, set to create the largest airline in the world in terms of passengers.

Both companies confirmed their stockholders' decisions, which were taken in separate annual meetings.

At an annual meeting held in New York, more than 98 per cent of Northwest stockholders favoured the merger, Northwest said. Northwest is the fifth-largest airline in the United States.

Delta shareholders meeting in Atlanta later ratified the merger, too.

The managements of the two airlines had come to an agreement in April, in a stock swap deal worth more than 3 billion dollars, according to the stock's value at the time. In practical terms, the deal is a purchase of the smaller Northwest by the third-largest airline in the United States.

All large legacy US airlines are currently in the red, amid high fuel costs, excess capacity and a slow US economy. The situation has led to thousands of layoffs, to the disappearance of many routes and to drastic fleet reductions. (dpa)