HANOI, May 6 (Reuters) - Vietnamese budget airline

Vietjet said on Tuesday it had bought a strategic stake in

Kazakhstan's Qazaq Air to form a joint venture that will operate

a fleet of at least 20 Boeing 737 aircraft.

Vietjet said the joint venture, Vietjet Qazaqstan, was part

of its international expansion plans. It didn't provide details

about the size of the stake it was buying in Qazaq Air.

"Vietjet Qazaqstan is a new generation low-cost airline,

expected to become a strategic aviation bridge between

Kazakhstan and Vietnam, Southeast Asia and international

aviation centres," it said in the statement.

The joint venture has signed a deal with Boeing ( BA ) for

services including software solutions, spare parts, technical

assistance, and training programs for pilots and engineers.