Activist investor Elliott Management Corp. is seeking to break up Noble Energy Inc.'s $5 billion sale to oil major Chevron Corp., a Bloomberg reporter tweeted on Sept. 9.

A notice posted on the U.S. Federal Trade Commission website on Sept. 8 showed the hedge fund had built a stake in Noble Energy.

In response to the tweet, Braden Reddall, manager, external affairs at Chevron, said the company's offer "represents a fair value for the business and that the transaction will create long-term value for shareholders of both companies."

"We continue to expect the transaction to close in the fourth quarter," Reddall added.

Elliott declined to comment. Noble Energy did not immediately respond to a Reuters request for comment.