Melbourne:Venus and Serena Williams will team up to play doubles at the Australian Open in Melbourne in January, organisers said on Thursday.
The American pair have not played doubles at the Australian Open since they won the title for the second time in three years in 2003.
They played their first doubles match together in four years at this year's Wimbledon before withdrawing in the second round because of injury, and have not been reunited since.
Organisers said because injuries have sidelined them from playing in doubles events for so long they now have a nominal ranking of 9999.
Australian Open tournament director Craig Tiley said their decision to play was great news for the opening grand slam event of 2008.
"The Williams sisters in full flight on the same side of the net is one of the great sights in tennis," Tiley said in a statement.
"They are also one of the most skilled pairings on the world circuit with an incredibly successful record in doubles."
The Williams sisters are one of only five pairings in women's tennis history to win a career doubles Grand Slam.
In all, they have won six majors (Wimbledon and Australian Open twice, US and French) and an Olympic gold medal in Sydney in 2000.