Residential property website Zoopla has bought rival Thinkproperty.com from the Guardian Media Group.
Thinkproperty.com is a property portal launched in 2006.
Zoopla intends to integrate the Thinkproperty.com brand and website.
As part of the deal Zoopla will also become the exclusive property search partner on the Guardian.co.uk website.
Alex Chesterman, founder and chief executive of Zoopla, said: “We are delighted to be leading the latest round of consolidation in this market as it reinforces our mission of delivering the best possible value to estate agents by increasing their exposure to a wider audience and offering them a broader range of services.
“We plan to continue to grow our traffic organically and look at possible further acquisitions as part of our commitment to become the most efficient marketing partner for
Zoopla is the 5th most visited property website and was launched last year.