Warren Buffett may have some competition for latest deal from an activist hedge fund manager

Berkshire Hathaway's $9 billion deal for the electricity transmission company Oncor is facing a challenge.

Elliott Management Corp., the activist hedge fund may be gumming up the works. Reuters reported Friday afternoon that the firm, run by billionaire Paul Singer, may consider a rival bid for Oncor. Elliott is a major creditor of Energy Future Holdings, which owns most of Oncor and has been working its way through bankruptcy court.

The report says Elliott thinks it can put together a higher bid than Berkshire, the Omaha-based conglomerate run by Warren Buffett. An Elliott spokesman wasn't immediately available.