Virgin Blue, the second largest Australian airline, today echoed the cautious outlook shared by its much larger rival Qantas, after also posting about 80% of its expecting earnings of the complete year in a return to profits during the first half of the company's financial year.

The airline group also revealed plans to expand its domestic business with an arrangement to purchase up to 50 additional Boeing 737 aircrafts.

In all, Virgin is currently responsible for the operations of one domestic carrier, two short-haul international carriers and a single long-haul international airline, V Australia, which started regular flights to the US about a year back.

Despite the fact that lower fuel costs and a cost-cutting program helped the airline record net earnings of $62.5 Million for the six months up-to December 31, 2009, outgoing Chief Executive Brett Godfrey has warned that the operator's profitability might come under additional pressure over the year.

"We have a seasonal business and our traditionally busiest part of the year is the December first half - that and ongoing strong price competition will likely see pressure maintained on yield improvement for the remainder of this year", Mr. Godfrey said.