The $6 million investment in SEAIR will give Tiger Airways a foothold in a potential high-growth market, its chief executive and President Tony Davis said in a joint statement.

"The Philippines represents a major market opportunity for low cost airlines," Davis said.

"With more than 7,000 islands, a population in excess of 90 million, plus another 11 million working and living abroad, the Philippines is an important market for both international and domestic aviation."

His counterpart at SEAIR, Avelino Zapanta, said Tiger's planned acquisition of a significant stake in his airline would help it expand services.

Low-cost SEAIR launched services between Clark airport in the northern Philippines and Singapore last December, using Airbus A320 aircraft, and this year began flying to Hong Kong.

The Clark-Hong Kong service will double to twice-daily from April 15 to meet strong demand, with the airline also planning to expand domestic operations, the statement said.

Tiger flies to 37 destinations in 12 countries in Asia and Australia.

In the Philippines, SEAIR currently flies to three destinations in the Philippines from Clark, plus from Manila to resort island Boracay.

The statement did not say when the planned purchase would be finalised, other than to say steps would be taken immediately to wrap up the deal.