The Philippines Civil Aeronautics Board (CAB) is conducting an inquiry into the partnership between Philippine carrier Seair and Singapore low cost carrier Tiger Airways.
"The partnership between Tiger and Seair has been questioned by local airlines," says a CAB spokeswoman. "They feel Tiger Airways is operating through Seair."
Writing on behalf of Philippine carriers, in a December 2010 letter Philippine Airlines (PAL) complained to the CAB that as soon as Seair commenced flights on the Manila Clark-Singapore route using two A-319s leased from Tiger, the Singapore carrier ceased its services on the same route.
"We are not conducting a full blown investigation, but an inquiry into how the partnership operates," she says.
The carriers can keep the partnership going while the inquiry is carried out.
A Tiger Airways spokesman says Tiger and Seair acquired all necessary approvals and permits before commencing operations.
"We've operated the service for almost a month now, starting with one flight a day and moving to two daily, and we're doing well," he adds.
Philippine carrier Seair started its first international flights between Clark and Singapore from 16 December, operating daily with the leased A-319 aircraft.
In November Tiger and Seair formed a marketing partnership, under which Tiger will market Seair's Singapore flights on its website. The two carriers also said they were likely to have a revenue sharing agreement.