ICQ, which is the preferred instant-messenger service for the online adult business community and reportedly has 100 million accounts registered, was first developed by the Israeli company Mirabilis, which is now owned by AOL.
AOL purchased the company in 1998 for $407 million.
Digital Sky also is an investor in Facebook, having purchased $100 million in shares to boost its stake in the company to as much as 3.5 percent back in July.
The first version of the program was released in November 1996 and ICQ became one of the first services of its type. ICQ is a homophone for the phrase “I seek you.”
ICQ, now at version 6.0, features include sending text messages, offline support, multi-user chats, free daily-limited SMS sending, resumable file transfers, greeting cards, multiplayer games and a searchable user directory.
News of the potential sale comes just five days after AOL completed its spinout from parent Time Warner.