The Philippines air force could issue a fresh tender for 18 combat helicopters, after an earlier competition for six aircraft was cancelled due to alleged irregularities in the bidding process.

"They are working on the request for proposals, but there is still no indication on when it will come out and who it will go out to," says a source close to the defence ministry. "However, it is now likely to contain a requirement for 18 helicopters at one go." Some 3.2 billion pesos ($80 million) has been allocated for the procurement, the source adds.

Manila had hoped to buy six helicopters for delivery from year-end in the first stage of the procurement, and order an additional 12 in 2009 as a follow-up order. But with the cancellation of the first stage, the delivery timetable has been compressed and the ministry feels that it makes more sense to buy all 18 helicopters at one go.

Investigations into the cancellation of a 1.2 billion peso contract for six MD Helicopters MG530Fs due to alleged irregularities in the bidding process are ongoing. The deal was scrapped after losing bidder PZL Swidnik, which offered its Kania design, claimed that the MG530F did not fulfill payload requirements. A review panel found flaws in the bidding process, with technical specifications allegedly altered mid-way through the competition.

Defence secretary Gilberto Teodoro has asked for patience as the investigation continues, saying that his ministry did not "want to take shortcuts". Observers point out that the tinge of corruption surrounding the Philippines' military procurements hinders its efforts to modernise its armed forces.

The country currently operates Vietnam War-era Bell UH-1H transport helicopters, plus MD520s and Sikorsky S-76 assault helicopters. It is also reportedly assessing the Chinese-made Harbin Z-9 for an eight-aircraft transport helicopter requirement for its army.