Mail.ru, one of the top-ranking portals and search engines in Russia, will postpone its planned London IPO until 2009. Sources say the company hopes to increase its value from $1.5 billion to $2 billion before going public.

The site hosts 6.2 million daily visitors and 14.7 million monthly visitors, eports the TNS Web Index (via Quintura). Its EBITDA margin was the highest of all major Russian internet companies in 2007 — 64 percent on revenues of $56 million.

Yandex, currently Russia's top search engine, is expected to release its $2 billion IPO on the NASDAQ this fall.

Earlier this month, Google purchased Russian contextual ad firm ZAO Begun, punctuating its intentions to get more serious about Eastern Europe. Begun was owned by Rambler Media, which ranked No. 10 in the European search market in May. (Yandex was third, beating both Yahoo and Microsoft.)