"Don't be surprised in the future if we order 30 new jets at the same time," said president Piyasvasti Amranand, as the flag carrier worked on finalising the next stages of fleet renewal that will begin in 2015.

The new planes, mostly wide-bodied, will replace older aircraft to reduce its average fleet age from 11.5 years.

Having a younger and more efficient fleet will enable THAI to better compete with arch-rivals such as Singapore Airlines and Cathay Pacific, whose aircraft are about six or seven years old, said Mr Piyasvasti.

In this region, the only airline THAI has a younger fleet than is Garuda Indonesia, said Mr Piyasvasti.

"By the end of this year, we should have a clear picture of the fleet we will acquire after 2014," he noted.

A draft plan presented to THAI's board shows by 2026, the airline expects to have a fleet of 102 aircraft with an average age of 7.5 years.

There are 88 planes in THAI's fleet, and over the next five years the airline will retire 25 aircraft.

Between 2015 and 2019, the carrier plans to retire 32 aging aircraft and acquire 38 new aircraft to replace them.

From 2020-24, 20 planes would exit THAI's fleet with 28 new aircraft entering.

The airline ordered seven A330-300s from Europe's Airbus last week.

The THAI board also approved a proposal to lease eight long-range Boeing B777-300ERs. The 15 new jets are due to join THAI's fleet in the next four years.