Delta Air Lines has signed an agreement with Singapore Airlines to develop passenger and cargo traffic between the United States and Southeast Asia.

Beginning May 1, the carriers will participate in joint promotional and advertising programs and joint fares, and will coordinate schedules and initiate a month-long flight attendant exchange program designed to promote and publicize each other's products and services.Already begun is an enhanced interlining program to speed passenger connections between Singapore Airlines' service to Los Angeles via Tokyo and Delta's service from Los Angeles to Atlanta and Dallas/Fort Worth.

Delta said a project team will be formed to implement the joint programs and explore opportunities for cooperation in other areas as well.

Singapore Airlines currently operates 500 weekly flights to 57 cities in 37 countries. Singapore Airlines also operates the world's youngest fleet of aircraft. Average age of its aircraft is 4.5 years.

Delta presently operates 2,300 daily flights with service to 161 cities in 12 countries. Delta has the youngest fleet among the major U.S. carriers, with an average age of 8.5 years.