Nearly a third of the island's electric customers remain without power four months after Hurricane Maria struck the island on September 20. Source: NYPA

Puerto Rico Gov. Ricardo Rosselló says he is moving to sell the U.S. territory's public power company.

Nearly a third of the island's electric customers remain without power four months after Hurricane Maria struck the island on September 20.

Rosselló said Monday that it might take 18 months to privatize the troubled Puerto Rico Electric Power Authority, or PREPA, one of the largest U.S. public utilities measured by number of customers, 3.3 million.

The realignment would occur in three phases, which Rosselló called a move toward a “consumer-centered model.”

Phase one consists of defining the legal framework via legislation. Phase two will evaluate bids, and phase three will be “the terms of awarding and hiring the selected companies that meet the requirements for the transformation and modernization of our energy system will be negotiated.”

In his address, the governor said privatizing PREPA would improve service, reduce the cost of electricity and increase investment in renewable energy.

"The Puerto Rico Electric Power Authority does not work and cannot continue to operate like this," Rosselló was quoted as saying. "With that PREPA, we cannot face the risks of living in an area of high vulnerability to catastrophic events."

Even before the hurricane, PREPA has had its problems. Its power generation plants burn expensive and polluting oil and its infrastructure averages about 45 years old, compared to about 18 years for utilities on the U.S. mainland, according to The Associated Press.

In October, PREPA hired Whitefish Energy Holdings, a Montana-based company with ties to Interior Secretary Ryan Zinke, to head up the effort to restore power. The $300 million contract drew criticism and in late October, Rossello announced the contract with Whitefish was being terminated.