Yahoo has filed an intellectual property lawsuit against Facebook.
Yahoo claims the social network has infringed 10 of its patents including systems and methods for advertising on the web. Facebook denies the allegation.
The move comes ahead of Facebook's planned flotation later this year.
Patent litigation has become common between the smartphone makers, but this marks a new front in the battles between the tech giants.
A statement from Yahoo suggested the web portal believed it has a strong case.
Full story:
http://www.bbc.co.uk/news/technology-17345935
