After the EU's acceptance of Microsoft's acquisition, Activision Blizzard will establish an office in Barcelona

Activision Blizzard said that its Call of Duty development studio would relocate to Barcelona, putting into reality a vow to invest in Europe made after Brussels approved Microsoft's $69 billion (roughly Rs. 5,66,000 crore) acquisition of the business in May.

On Wednesday, the US business said that Infinity Ward, the creator of the hit first-person shooter game, will join its Digital Legends mobile games branch in the Spanish city.

The move comes after the United Kingdom denied Microsoft's merger, forcing Activision, which has facilities in Guildford and Warrington, England, to warn it will "reassess" its expansion ambitions in the nation.

In contrast, it stated that if the agreement is approved in the European Union, it will "significantly expand" its investment and employment there.

Microsoft and Activision Blizzard are battling antitrust authorities on both sides of the Atlantic to complete the largest video game merger ever.

Activision Blizzard CEO Bobby Kotick and Microsoft CEO Satya Nadella are scheduled to appear in a San Francisco court on Wednesday to urge a judge to approve the merger.

The Federal Trade Commission, which is attempting to halt the transaction, wants the transaction to be halted temporarily so that the matter may be decided by the agency's in-house court.

Microsoft is challenging the British veto with Activision's "aggressive" backing.

After the acquisition was vetoed, the gaming giant, which also owns the Candy Crush Saga and World of Warcraft properties, declared that Britain was "clearly closed for business" in April.

It said on Wednesday that it was looking into expanding its studio footprint in the EU.

"For good reason: Europe has played a key role in the evolution of gaming — particularly mobile gaming — across the globe, and it's not unreasonable to expect developers on the continent to maintain that momentum thanks to ample skills, ambition, and government support," the company wrote in a blog post.