UPDATE (9:23 A.M. ET): Here are the reported details of the trade that will send Khalil Mack to the Bears:

ORIGINAL STORY: Khalil Mack reportedly is on the move.

The All-Pro edge rusher has been holding out during the preseason in hopes of landing a lucrative contract extension with the Oakland Raiders. But the Raiders on Saturday agreed to trade the 27-year-old to the Chicago Bears, ESPN’s Adam Schefter reported, citing sources.

While the deal seems like a virtual certainty at this point, there still are some details to work out.

The Bears have permission to work on a contract with Mack, NFL Network’s Ian Rapoport reported. Negotiations have been ongoing since Friday night.

Assuming the trade eventually is completed, the Bears have landed themselves one of the NFL’s elite defensive talents.

Mack has averaged 12 sacks over his last three seasons with the Raiders. The University of Buffalo product has 40.5 sacks and 231 tackles over his four-year career.

Thumbnail photo via Sergio Estrada/USA TODAY Sports Images