Enterprise Product Partners approached Williams Companies earlier this summer about an acquisition that would combine the two U.S. oil and gas pipeline companies, people familiar with the matter said on Wednesday.
Shares of Williams spiked more than 11 percent on the report, but later pared those gains and ended the day up nearly 8 percent. Enterprise shares were slightly higher in intraday trade on Thursday, but later reversed and ended the session down nearly 2 percent.
A rise in Williams' shares over the last two months means that Enterprise Product Partners's offer currently carries little or no premium, and Williams never made an official response to the approach, one of the people said. Enterprise Product Partners has not pursued the matter further either, the source added.
The sources asked not to be identified because the discussions were confidential. Enterprise Product Partners and Williams offered no immediate comment.
Although Williams shares are down more than 47 percent in the past year, they have gained more than 76 percent in the last six months, according to FactSet.
— CNBC.com contributed to this report.