March 8 (Reuters) - Royal Dutch Shell Plc and American private equity firm Blackstone Group LP are working on a joint bid for BHP Billiton Plc's U.S. shale assets for $10 billion, Sky News reported.
The shale auction is expected to lead to a deal later this year, Sky News said.
BHP had put up the U.S. shale assets for sale last year.
BHP declined to comment. Shell and Blackstone could not be immediately reached for comment.
(Reporting by Sangameswaran S in Bengaluru Editing by Susan Fenton)