Australia's second largest airline, Virgin Blue, has decided to purchase the 105 Boeing 737 aircraft. It is attempting to upgrade its fleet. This overhaul is the largest since the launch of the airline a decade ago.

The company has not divulged details about the value of the deal. However, the airline maintained that if its demand is considered and fulfilled it would be largest order that Boeing order has received in the past 18 months.

The agreement, which took place this year, encompasses 50 firm orders, 25 options and purchase rights for 30 aircrafts in the future. The delivery of these aircrafts is scheduled from 2011 to 2017.

It has been reported that Virgin Blue is making attempts to provide competition and take over the market share of Qantas Airlines. Qantas is Australia's leading airline.

Virgin Blue is also trying to eliminate competition from new entrants in the market which include Singapore's Tiger Airways.

The company states that new aircrafts were required "to aggressively ensure market share is not eroded and to provide additional growth options".

It is also expected that Virgin Blue will renew its attempts to encroach on Qantas territory when John Borghetti takes over as the Chief Executive next month.