Exclusive availability of the first Android-based handset and the ever popular Apple iPhone helped propel T-Mobile’s wireless subscribers upward during 2008.

T-Mo’s mobile customers at the end of 2008, topped out at 128.3 million, up 6.3 per cent year on year.

The firm’s US mobile subsidiary was the first operator to launch the T-Mobile G1, based on Google’s Android, on October 22. By the end of the year, subscribers to T-Mobile USA hit 32.8 million, following the addition of 621,000 new customers during the final quarter of the year. The operator didn’t say how many G1s it shifted but, manufacturer HTC hinted that it had shipped 1 million gadgets worldwide by the end of the year.

Over in the operator’s domestic market, Germany, the iPhone 3G and the G1 made significant contribution to increasing competitiveness, where T-Mobile added over 950,000 new customers during the fourth quarter.

Parent firm Deutsche Telekom also reported that international fixed line broadband users increased 8 per cent year on year to 15 million, while traditional fixed lines dropped 7.5 per cent to 33.8 million.