International oil company ConocoPhillips said today it will sell all its interests in the San Juan Basin, which sprawls across southwestern Colorado and into New Mexico, to an affiliate of Hilcorp Energy Co. for up to $3 billion.

The sale by Houston-based ConocoPhillips (NYSE: COP) will be for $2.7 billion in cash with a contingent payment of up to $300 million, depending on closing adjustments, on top of that.

When the deal closes, which is expected in this summer, the primarily natural gas assets will be owned by Hilcorp San Juan LP, a partnership between Houston-based Hilcorp Energy and Washington, D.C.-based private equity firm The Carlyle Group (Nasdaq: CG).

Privately held Hilcorp Energy is led by CEO Jeffery Hildebrand, one of the richest billionaires in Houston, with a net worth of $4.3 billion, according to Forbes.

Read more at Denver Business Journal.