Among the most hyped acquisitions in UK online space has finally happened:  ITV, Britain’s largest commercial TV broadcaster, agreed to buy community site Friends Reunited for as much as 175 million pounds ($304 million).

The initial payment will be 120 million pounds, with an earnout of 55 million pounds may be made during 2009 based on performance targets.

Friends Reunited helps people find colleagues from school, military service or other previous stages in their lives, and now has 15 million registered U.K. members and 1 million paying subscribers who get full access to its sites. The company now has five units: Friends Reunited, genealogy site Genes Reunited, Friends Reunited Dating, Friends Reunited Jobs and Connections, a networking site.

Friends Reunited combined with ITV.com, the broadcaster’s site, becomes Britain’s eighth-largest online operation in terms of unique users, the company said.

FT: Friends Reunited will bring ITV an increased opportunity to sell online advertising. It could also provide opportunities to promote ITV programmes and channels online, and investigate tie-ups between ITV’s local broadband channels and Friends Reunited communities.

More details in company FAQs here...