A group of Cobb EMC customers asked the Federal Energy Regulatory Commission on Tuesday to investigate the Marietta-based electric co-op, saying they believe it has violated the Federal Power Act.

FERC has regulatory authority over Cobb EMC, the monopoly power provider for most of nearly 200,000 customers in Atlanta’s northwest suburbs.

Cobb EMC customer Mark Hackett said he hopes a FERC probe would shine light on the customer-owned co-op’s spending, including its spending on one or two new coal plants in South Georgia.

Cobb EMC spokesman Sam Kelly said the group is part of a radical environmentalist effort to stop the plants.

A FERC spokesman said the agency had no comment on the request.

The group said Cobb EMC failed to make required disclosures to FERC and that interlocking relationships that led to a suit and criminal charges violate federal bans on using monopoly utility resources to subsidize side ventures and buy non-utility services at non-market rates.

Customers have struggled for control of the co-op since August 2007, when The Atlanta Journal-Constitution revealed conflicts of interest and potential management self-dealing  based on the relationship between the nonprofit co-op and a for-profit operating company controlled and partly owned by co-op management.

A customer lawsuit followed.

Despite a 2008 settlement and a 31-count racketeering and theft indictment against CEO Dwight Brown, the same board and management remain in control.

The settlement required elections allowing customers to vote on the board, but they've been stalled in court.

The settlement required Brown to leave by February. He retired that month, but the co-op board rehired him as a consultant with the same duties the same day. It has petitioned to rehire him as CEO.

A Cobb judge dismissed Brown’s criminal indictments on a technicality. Prosecutors are appealing.

Co-op customers elect their boards, so co-ops don't face the same state regulation as Georgia Power.