Singapore Airlines, the world's second-largest carrier by market value, is expected to start its new budget long-haul carrier in April with one Boeing 777-200 aircraft, the Straits Times reported on Tuesday.

The number of aircraft operated by the new airline will be expanded to four within three months and to a total of 14 Boeing passenger jets, with a capacity to carry around 400 passengers each, by the middle of 2016.

The success of the new budget carrier could give SIA a new growth engine and an ability to compete with rising competition from other budget carriers such as AirAsia and JetStar, a unit of Qantas.

SIA officials were not immediately available for comment.