Nokia Siemens Networks has said that its planned acquisition of Motorola’s wireless infrastructure assets will not now complete in the first quarter of this year, as it had previously predicted. The deal had already been pushed back from the fourth quarter of 2010 and NSN is now offering “no further guidance” on when it may be finalised, stressing only that it remains committed to the acquisition.

The deal has been delayed by the Chinese Anti-Monopoly Bureau, part of the Ministry of Commerce, which is taking longer than anticipated to complete its review of the acquisition, which was set in motion in July last year.

This latest delay is set against a backrop of conflicts between Chinese state and industry and Western counterparts. Chinese vendor Huawei has won an injunction against Motorola relating to the NSN sale, requiring proof that intellectual property that Huawei licensed to Motorola does not transfer to NSN as part of the acquisition. Huawei itself was recently forced to withdraw from its proposed acquisition of 3Leaf by the US Committee on Foreign investment, meanwhile.

This prompted the firm’s deputy chairman to write an open letter to the US authorities challenging them to present proof that Huawei has links to Chinese military and intelligence services – accusations that have dogged the vendor as it seeks to build its business in the West.

In February the European Commission published findings suggesting that Huawei and compatriot vendor ZTE are state-controlled and receive cheap government loans that give them an unfair advantage over European competitors. This prompted China to warn of retaliation if the findings were acted upon, with the allegations that EU subsidies for European vendors breach WTO rules.