Infrastructure vendor Nokia Siemens Networks has seen its acquisition of Motorola’s network assets delayed until the first quarter of 2011. The company is still waiting for regulatory approval from the Anti-Monopoly Bureau of the Ministry of Commerce of China, which was expected to complete its review before the end of 2010.

NSN paid $1.2bn to acquire the assets in July 2010, through which it expects to gain new relationships with 50 wireless carriers and strengthen existing commercial ties. Motorola’s networks portfolio caters to a range of technologies, from GSM and CDMA, through WCDMA to WiMAX and LTE. The US vendor will be keeping hold of its iDEN business, however, and will also retain most of the patents related to its wireless network infrastructure business.

“This delay is disappointing, but we’re looking forward to completing the acquisition early in the new year,” said Rajeev Suri, chief executive officer of NSN. “We are continuing to work closely with the authority in China to finalize the clearance process in that country.”

Approximately 7,500 employees are expected to transfer to NSN from Motorola’s public carrier wireless network infrastructure business when the transaction closes, including large research and development sites in the US, China and India.

On Tuesday, Motorola completes its separation into two separate companies: Motorola Mobility, focusing on handsets and consumer devices; and Motorola Solutions, which develops equipment for public and enterprise organisations.