The deal is subject to approval by regulators
Television company CBS has agreed to buy technology news and entertainment website CNET for about $1.75bn (£900m).
CBS said that the purchase of CNET, which owns sites such as ZDNet and Gamespot, would help to boost its online presence.
CBS has offered $11.50 a share in cash, which is 45% more than CNET's closing price on Wednesday.
The companies said the combined group would have "significant additional exposure" to online advertising.
The deal will make CBS "one of the 10 most popular Internet companies in the United States", with 54 million US users and 200 million worldwide, CBS said in a statement.
The deal is subject to approval by regulators and CNET shareholders.
Other CNET sites include News.com, TV.com, Mp3.com and MySimon.
CBS will combine them with its own websites such as CBSSports.com and CBSNews.com.