HELSINKI (AFP) - A Swedish woman gave birth to a healthy baby girl while flying at 11,000 metres (37,000 feet) over Kazakhstan en route from Thailand to Helsinki, the Finnair airline said Friday.

"This is the first time this has happened on our airline," Finnair spokeswoman Hanna-Kaisa Nurmi told AFP, adding that to her knowledge such mid-air births happen "only rarely if ever."

Fortunately, there were two doctors and two nurses on Thursday's flight who helped with the birth, while a physician working for US company MedLink was available to lend a hand via satellite link.

"But the delivery went so well that plan B, which was an emergency landing in Moscow and the use of MedLink, was not needed," Nurmi said.

On arrival at the Helsinki-Vantaa airport at 1620 GMT after a nearly 11-hour-flight, the exhausted mother and her newborn daughter were taken to hospital.

As a birthday present, Finnair has offered the whole family return tickets to Bangkok, but it remained unclear if they would take the company up on its offer.

Pregnant women are generally not permitted to fly without a doctor's certificate after the 26th week of their pregnancy and are banned from all longer flights after the 36th week, or a month before the baby is due.

Finnair however permits women to fly shorter distances up until two weeks before their due-dates.

It remained unclear how many weeks pregnant the Swedish woman was when she gave birth in mid-flight on Thursday.