Access Industries Inc. received approval from the Federal Energy Regulatory Commission on Feb. 16 to exercise an option to expand its governance rights in Volt Parent LP.

Volt Parent, a wholly owned subsidiary of Energy Capital Partners, is among a group of investors acquiring a 95.1% controlling stake in Calpine Corp. in a $5.6 billion private buyout. That deal is under FERC review. Under the transaction, Access Industries will convert its 13.8% passive stake in Volt Parent into an active interest.

Access Industries can complete the transaction only after the Energy Capital Partners-led group has acquired Calpine and its 26,000-MW portfolio that includes natural gas-fired and renewable assets across the U.S. and Canada, according to the filing.

The merger transaction is expected to complete by March 31. (FERC docket EC18-39)