Houston-based private equity Post Oak Energy Capital LP on Monday said it led a $100 million equity commitment to Saxet III Minerals LLC, its third with the U.S. onshore oil and gas focused operator.

The management team of Saxet, also based in Houston, plans to co-invest with Post Oak to acquire and manage mineral and royalty interests in U.S. basins.

The first two exploration and production (E&P) entities, Saxet Minerals LLC and Saxet II Minerals LLC, have aggregated core positions in Oklahoma’s stacked plays, in the Permian Basin’s Midland formation of West Texas and in North Dakota’s Bakken and Three Forks formations.

“The long-standing partnership with Post Oak has been instrumental in helping Saxet create significant value in the minerals space,” said Saxet President Robert E. O’Brien. Since Saxet’s inception in 1992, O’Brien has co-founded, developed and sold other related companies.

Post Oak’s E&P investments have included Chaparral Energy Inc., CP Exploration II LLC and PetroEdge Energy III LLC. In the midstream arena, Post Oak helped finance Oryx Midstream Services LLC.

Post Oak has also helped kickstart Balcones Energy Holdings LLC, Core Minerals Management II, Cornerstone Petroleum Resources, Crown Oil Partners VI, Exponential Resources LLC, Mavros Minerals, Rimrock Resource Operating LLC, UpCurve Energy LLC and Veritas Energy Partners LLC.

“Securing mineral and royalty interests is an integral part of the E&P industry, and we recognized early on that Saxet’s approach and experience would uniquely position Post Oak’s portfolio,” said Post Oak managing director Frost Cochran.