"Russians in the City" is a non-commercial informal organization of Russian-speaking people working in the United Kingdom, mainly in London, in financial sector. It includes traders, solicitors, stock analytics, journalists, auditors, IT workers and others. It doesn't have a formal agenda aside from networking, helping each other and having fun together. Drinking parties are held every 1.5 - 2 months. Photos from a recent party can be found here, and here you can access photos from other parties.

You also might be interested in regular meetings of Russian-speaking professionals in Canary Wharf [in Russian].