MML Capital Partners is buying Apache Industrial Services Inc. for an undisclosed amount.

Houston-based Apache provides refractory, fireproofing, scaffolding, coatings and linings, abatement and insulation services to the refining, chemical, power and industrial sectors.

The investment was led by MML and included Apache’s management team, and two MML limited partners – GoldPoint Partners and Cigna Investment Management. MML made the investment from its fifth fund. The London private equity firm has also invested in ATA Group, FrontierMedex and Par Systems.

PNC Bank NA provided senior financing for the transaction.