SAN FRANCISCO — Yahoo's board of directors has approved a $1.1 billion cash acquisition of the popular blogging site Tumblr.
It's the biggest and riskiest deal yet for Yahoo chief executive Marissa Mayer, who is trying to make the pioneering Internet company relevant to young people who have gravitated to other services and to mobile devices.
The board of the Sunnyvale, Calif., company met Sunday to consider the transaction, which Mayer negotiated. The deal — a major statement about the direction she plans to take Yahoo — is expected to be announced today.
In an invitation sent to the news media Friday, Yahoo promised to announce "something special" late today in New York. The event is being held 2 miles from Tumblr's headquarters.
Tumblr is enormously popular with teenagers and young adults, a key demographic that Yahoo must reach to pull out of a prolonged slump.
Tumblr was founded in February 2007 by David Karp, who is 26. Tumblr has ridden its popularity to acclaim but has failed to establish a thriving advertising business.
Since she took over Yahoo in July, Mayer has focused on redesigning Yahoo services to focus on mobile and to attract mobile engineers, mostly through the acquisition of tiny startups. In just the first three months of this year, Yahoo bought three startups for a total of $10 million.
Investors are backing Mayer's strategy. Yahoo's stock price has risen 69 percent since the former Google executive took command of Yahoo.