Australian carrier Optus intends to double the amount of available 3G spectrum it owns in the country’s capital cities, by buying licenses from US chip vendor Qualcomm.

Qualcomm acquired the 2x10MHz licenses for 2100MHz spectrum in the Australian 3G wireless spectrum auctions back in 2001 for A$159m ($137m today, but $79m back then). Qualcomm originally planned to deploy a cdma2000 1x EV-DO network in 2002 through its wholly owned 3G Investments vehicle but thought better of the idea.

Financial terms of the deal with Optus have not been disclosed, but the move will double the operator’s capacity in the capital cities. The carrier would use the extra spectrum to support demand for wireless data services in both the wholesale and retail markets.

Optus is the country’s second biggest mobile operator behind Telstra, with 9.5 million subscribers at the end of 2009 according to Informa’s WCIS.