SAN FRANCISCO (AP) -- Google is buying Silicon Valley startup Meebo to help expand its social networking service.
The acquisition announced Monday will mean more tools for Google Plus, an alternative to Facebook's popular online hangout. Meebo started out as a system for connecting people on instant messaging, but has since built other communications features that are now used by about 100 million Web surfers in the U.S.
Both companies are based in Mountain View, Calif.
Financial terms of the deal weren't disclosed. Meebo has raised $70 million in venture capital since its inception in 2005.
Google Inc. has spent more than $16 billion buying 140 companies since the end of 2009. That includes the biggest deal in Google's 14-year history, a just-completed $12.5 billion acquisition of cellphone maker Motorola Mobility Holdings.