Delta Airlines said yesterday it had placed a firm order for 106 planes with Boeing and taken options on 124 additional aircraft in a deal worth a potential $15 billion (£9.4 billion).

The third-largest US carrier said it had agreed to make Boeing its exclusive supplier of new aircraft over the 20-year life of a "fleet acquisition plan".

It said 106 planes would be ordered by the year 2006 at a value of $6.7 billion dollars. Including purchase options on 124 additional Boeing aircraft, the deal could be worth a total of $ 15 billion.

"This flexible and disciplined fleet acquisition plan gives us the right aircraft at the right time and at the right price to build on Delta's competitive advantages as we put our global strategy in place," said Mr Ronald Allen, Delta chairman.