BHP Billiton Ltd. is holding discussions with competitors on the future of parts of its U.S. shale business amid heightened scrutiny of the unit from shareholders, including activist investor Elliott Management Corp. The company recognizes it needs alternative strategies for some of the assets, particularly gas-focused operations, Chief Executive Officer Andrew Mackenzie told reporters Monday in Tokyo. The were multiple potential owners of the assets spread across the states of Texas, Arkansas and Louisiana, he said. “We are in regular dialogue with those natural owners as to whether or not we can form more collaboration to allow us to share facilities,...