Holidays Reunited will allow members to get in touch with people they met on holiday and provide a community area to share holiday news, photos and travel blogs.
The site was developed after research showed that 61% of people asked would use a service that helped them find old friends they met on holidays and 46% have met someone on holiday they would like to get in contact with.
Vanessa Kent, controller of online sales at ITV, said: "We identified a definite gap in the market based on research carried out with the Friends Reunited database and it was clear there is an appetite for this type of content. For advertisers it will provide a captive audience and the opportunity to reach users engaged in the travel social network."
According to Friends Reunited head Jon Clark, more than one million profiles are updated every month on the site as members come back to keep their friends abreast of the latest news, including sharing their recent holiday photos.
"On average, members register against three lists from the school they attended to university to the street they once lived on. This new service will enable them to reunite with even more old friends and acquaintances," Clark said.
In 2007, January registrations to the reunion site were up 74% with 5.7 million unique users and 275 million page impressions. Of the adult online population, 61% are now members of Friends Reunited with one in three adults online visiting over a two-month period. Other spin-off sites include Genes Reunited, Friends Reunited Dating and Friends Reunited Jobs.
Friends Reunited founder Steve Pankhurst helped fund the launch of a similar site, WAYN, in May 2003. In January this year, WAYN received $11m from a team of investors including lastminute.com co-founder and former chairman Brent Hoberman who is now chairman of WAYN. The site has grown from 45,000 users in March 2005 to more than seven million today.
Friends Reunited was sold to ITV for £120m in December 2005.