Alcatel-Lucent has closed its acquisition of Nortel Networks's universal mobile telecommunications system (UMTS) mobile infrastructure business, the companies announced Tuesday.

Alcatel-Lucent announced plans to buy the third-generation (3G) networks business in September for $320 million (£164.5m), less transaction costs. The deal cleared the final regulatory approvals and closed the purchase on 31 December, it said.

The company also said the deal makes Alcatel-Lucent one of the largest providers of UMTS gear, with one in four UMTS operators worldwide using its products.

Nortel had failed to establish a leading position in the 3G market and will now focus instead on what it calls 4G mobile technologies, including WiMax, (EV-DO) evolution-data optimised revision C, and the long-term evolution (LTE) generations of UMTS. It will also continue to support customers using earlier Code Division Multiple Access (CDMA) and Global System for Mobile Communications (GSM) technologies.

About 1,700 employees from Nortel's UMTS unit are moving to Alcatel-Lucent, including most of the research and development team, the companies have said.

Alcatel and Lucent completed their merger in November.