The commercial broadcaster has appointed Credit Suisse as its exclusive financial adviser on the sale, which has been codenamed Project Finland.
Credit Suisse sent out a taster document earlier this month and interested parties had until 9 April to express their interest, ahead of a formal two-stage sale process.
The document spells out what ITV believes are significant opportunities for future growth, such as using the Friends Reunited database to move into new markets through strategic partnerships. It is already exploring shopping, travel, gaming and paid-for surveys.
ITV also believes a dedicated online sales team could increase revenues as opposed to the TV specialists who have been selling the website's ads.
The Friends Reunited Group, which also includes Genes Reunited and Friends Reunited Dating, made £8.8m EBITDA on revenues of £17.8m in 2008 and has more than 30 million registered users.
ITV bought the business for £120m in late 2005 but has seen rivals such as Facebook and Bebo steal a march on it since. Analysts expect the business is now likely to fetch £40m at most.
ITV announced it was looking to sell Friends Reunited in its annual results on 4 March, along with online search directory Scoot. The broadcaster has also scaled back grassroots news service ITV Local and closed multimedia gaming division ITV Play.