Nokia Siemens Networks’ $1.2 billion acquisition of Motorola Solutions’ networks business hit another snag after China’s antitrust authority decided to extend its review of the deal.

The Chinese Ministry of Commerce (MOFCOM) will review the sale for up to an additional 60 days, stopping Nokia Siemens from completing the acquisition within the first quarter of this year as planned. The deal must receive anti-trust approval from the Chinese regulatory authorities before it can close.

In a statement, Nokia Siemens said it “remains committed to the acquisition but will provide no further guidance on when it is likely to be completed.” The deal is in the third phase of the review process for MOFCOM’s anti-monopoly division, Nokia Siemens said.

Motorola Solutions also issued a brief statement on the delay, saying it will “continue to work with MOFCOM to pursue approval of the transaction.”

The MOFCOM decision came after China-based infrastructure company Huawei filed a suit in a U.S. District Court to block the deal, alleging Motorola would release Huawei’s trade secrets to Nokia Siemens if the acquisition went through. A judge later ordered Motorola to not disclose Huawei’s confidential information to Nokia Siemens but did not block the deal from going through.

Motorola’s network business used Huawei’s intellectual property rights and sold rebranded Huawei equipment over a 10-year period beginning in 2000. Huawei is concerned that Motorola may leak its trade secrets to Nokia Siemens if the sale of Motorola’s networks business goes through.