Rebranded from Alfa Telecom last year, the £5bn investment house is part of the £19.5bn Alfa Group, and has stakes in some of eastern Europe's biggest telcos.
Apco director Simon Whitehead said his agency, which was appointed by the then Alfa Telecom 18 months ago, would continue to work with Alfa Group and Altimo. But he declined to say what that support would involve.
Altimo owns 33 per cent of Russia's second biggest mobile operator VimpelCom. Last year it bought a 13 per cent stake in Turkish operator Turkcell for £1.8bn – the highest price ever paid by a Russian company for foreign assets.
Brocklebank-Fowler said Altimo was keen to grab a bigger slice of the underdeveloped Eurasian market. Cubitt's remit covers financial, corporate and government comms across the UK, Europe and North America.
Altimo's subscriber base is around 100 million people, from Russia, Turkey, Sweden and the Ukraine, but the firm is hoping to cash in on a rapidly expanding eastern European market.
The number of mobile subscribers in Russia alone rose by 20 million to 60 million last year.
The Eurasian telco market is volatile and highly litigious. Earlier this week Altimo scored a victory over Norwegian rival Telenor in the Ukrainian High Commercial Court.
The firms were in dispute over board composition and voting rights for Ukrainian mobile telco Kyivstar, jointly owned by both – with
Telenor controlling a majority 56.5 per cent.
Cubitt reports to Altimo chief executive Alexey Reznikovich.