The British government has approved U.S. asset manager Advent International Corp.'s acquisition of U.K. aerospace and defense firm Cobham PLC.

The private equity firm made commitments to address national security concerns, the U.K. government said Dec. 20.

"I am satisfied that the undertakings mitigate the national security risks identified to an acceptable level and have therefore accepted them and cleared the merger to proceed," Business Secretary Andrea Leadsom said.

"The companies have given a legally binding commitment that there will be significant protection of jobs and have also agreed with the Takeover Panel that Cobham’s headquarters will remain in the U.K., that the Cobham name will continue to be used and that there will be a guaranteed level of R&D spend. This will secure the future of Cobham and the important role it plays in our world-leading defense sector and economy," she said.

The European Commission approved the deal in October.

Advent agreed to buy Cobham in July for £3.9 billion at a per-share price of £1.65. Authorities in the U.K. had been ordered to review the deal in September after Cobham's shareholders approved the takeover.