"Nokia Siemens Networks remains committed to the acquisition but will provide no further guidance on when it is likely to be completed," the company said in a statement, adding that they were still waiting for approval from Chinese regulatory authorities.

When NSN originally announced the deal last July, it expected the deal to be completed by the end of 2010 but this was delayed until the end of the first quarter of 2011 as it waited for Chinese anti-trust approval.

The companies had announced on July 19 that NSN would buy most of Motorola's wireless network infrastructure assets for $1.2 billion (926 million euros), bolstering its ranking as world number two in the industry.

On December 15, the European Commission gave the green light to the transaction, saying it would "not significantly impede effective competition in the European Economic Area (EEA) or any substantial part of it."

The deal has also received the approval of regulators in the United States, Brazil, Japan, Russia, South Africa, Taiwan and Turkey.