Brightsolid believes the site will boost genealogy research
Scottish publishing giant DC Thomson is buying the social networking website Friends Reunited from ITV for £25m.
The broadcaster paid an initial £120m for the site in 2005, and gave an additional £55m earlier this year.
However, competitors such as Facebook and Bebo have been eating into Friends Reunited's share of the market.
Brightsolid, which is a subsidiary of Dundee-based DC Thomson, will use the site to boost the web service it offers to family history researchers.
Friends Reunited was launched in 2000 to put old school friends back in touch with each other and sister site Genes Reunited was launched in 2003.
Brightsolid already has a role in genealogy websites findmypast.com, which contains census data, and Scotland's People, which contains information on events such as births, marriages and deaths.
The firm said its acquisition of the Friends Reunited Group would create Britain's largest genealogy business.
Chris van der Kuyl, chief executive of Brightsolid, told BBC Scotland he believed it was a wise purchase, despite the increasing social networking competition.
"People recently have written off Friends Reunited, it's far from written off, it's still a huge brand," he said.
"Three million people a month actively use the website and it's a wonderful place for us to take 20 million users and help them find different ways to communicate with friends, family etc.
"We paid what we believe is a fantastic price for this business and we've got a tremendous opportunity here to do something quite spectacular with this business.
"This one [social networking site] in particular has been around since the turn of the millennium, it's the granddaddy of social media sites and it's still strong."
Mr van der Kuyl believes Brightsolid can succeed where ITV failed.
"Brightsolid is an online innovation company, that's all we do," he said.
"We're totally focused on digital media, we are already profitable and successful in the area of digital media, these are profitable businesses."
Competition authorities will have to clear the deal before it can be finalised.