A Pratt & Whitney Canada engine designed for business jets is to power the launch plane for what is described as the world's first commercial passenger suborbital space ship.

The Longueuil, Que., company announced Wednesday that its PW308 turbofan has been selected for the White Knight II, part of a space tourism venture backed by British entrepreneur Richard Branson.

Britain's Richard Branson says Canadian-made jet engines will "help make our aerospace adventure a true success."

The yet-to-be-flown aircraft would lift the proposed SpaceShipTwo to 15,200 metres and release it for flights costing $200,000 a passenger.

Branson, founder of the Virgin companies and co-founder of the Spaceship Company, called the PW308 "the best and most reliable solution available today to help make our aerospace adventure a true success."

"We are delighted to welcome Pratt & Whitney Canada on board the White Knight II program," he said in a joint statement with the Canadian company.

PW300-series engines have already been used on Dassault Falcon, Bombardier Learjet, Cessna Citation and Gulfstream G200 jets.

Pratt & Whitney, a unit of Connecticut-based United Technologies, said the first flight of the White Knight II is planned for 2008.

Branson's Virgin Galactic venture has received "over $25 million US in deposits and interest" from 80,000 would-be space passengers, the statement said.

"Virgin Galactic will commence commercial operations as soon as development and testing of the system is complete," it said.