Facebook is in talks on a potential $1 billion deal to buy the Israel-based GPS mobile navigation app Waze, The Wall Street Journal reported.

The report late Thursday, citing unnamed sources, said the discussions were "serious" but that no deal had been finalized.

Waze, which claims more than 40 million users, could allow the world's biggest social network to expand its offerings in areas such as driving directions, or avoiding traffic jams or car accidents.

Waze describes itself as an app bringing together "the world's largest community of drivers who work together to fight traffic, and save time and gas money on their daily commute."

Facebook declined to comment on the report.

The Journal said Facebook could use the app to expand its mobile offerings and get a foothold in the field of online maps.

It would one of the biggest deals ever for Facebook, which last year took over Instagram in a stock deal initially pegged at $1 billion, hut with a final value of $747 million due to the drop in Facebook shares.

Facebook shares were down 1.08 percent at $26.75 in midday trade.