Once upon a time, ICQ was synonymous with instant messaging. While ICQ doesn't have this kind of clout anymore, it is still very popular in Russia and other countries that use the Cyrillic alphabet. AOL bought ICQ in 1998 for $287 million, but the company has been trying to sell ICQ for quite a while. After a short bidding war between China's Tencent and Russia's Digital Sky Technologies and ProfMedia, AOL just announced that it has sold ICQ to Digital Sky Technologies (DST) for $187.5 million.

DST's Investment: Facebook, Zynga, Groupon

DST, of course, is also famous for making a major investment in Facebook last year and earlier this month, the Russian telecom giant also invested in Internet coupon site Groupon. DST also holds a stake in Zynga.

According to DST's CEO Yuri Millner, "the acquisition of ICQ is a strategic enhancement of our business in Russia and Eastern Europe. ICQ's long-standing brand name and its sizeable loyal customer base together represent a very attractive opportunity to further strengthen our position in the region."

Given ICQ's popularity in Russia, DST was probably the best buyer for the instant messaging service. It's unlikely, however, that DST will try to make ICQ a worldwide player in the instant messaging market again.