Genuine Parts Co. (NYSE:GPC) shares fell 1.09% to $131.13 in after-hours trading on Thursday, reversing a 12.9% intraday surge.

O’Reilly Bid Sparks the Rally

The stock move came as Bloomberg News reported on Thursday that O’Reilly Automotive Inc. (NASDAQ:ORLY) submitted a cash bid for GPC’s automotive parts unit, citing people familiar with the matter.

According to the report, the unit could be valued at $10 billion or more. A deal could be announced by the end of summer, though Genuine Parts may still keep the business or pursue a spinoff instead.

Genuine Parts and O’Reilly Automotive did not immediately respond to Benzinga‘s requests for comment.