Uber to allow users to "hail " minicabs directly from the FaceBook Messenger app.
The new service means Messenger users will be able to ask for an minicab without leaving the Facebook software.
Users will not need to download the Uber app separately. (So are Uber now venturing into the instant hail cash market....is this legal)
"Uber on Messenger" began in parts of the US this week, the two firms said.
The companies announced their new venture via separate blogs.
Facebook has some 1.5 billion users globally and Uber is the world's biggest minicab-hailing app in terms of financing.
Facebook explained how the service will work in this video.