The director of Puerto Rico's power company resigned on Friday amid ongoing blackouts and scrutiny of a contract awarded to a small Montana-based company to help rebuild the electric grid destroyed by Hurricane Maria.

Puerto Rico's Electric Power Authority (PREPA) said Ricardo Ramos presented his letter of resignation to the company's board effective immediately. Officials said Ramos would soon provide additional information.

Gov. Ricardo Rossello briefly told reporters that Ramos is a professional who worked hard to bring power back to Puerto Rico, but that "there were a series of distractions, and a decision was taken to go in another direction."

"That resignation was taken … in the best interest of the people of Puerto Rico," he said, adding that an interim director would soon be appointed.

Ramos testified before a U.S. Senate committee earlier this week about a $300 million contract awarded to Whitefish Energy Holdings that has since been cancelled. The contract is undergoing a local and federal audit.

Prior to the announcement of Ramos's resignation, local newspaper El Vocero had reported on Friday that Ramos had awarded a nearly $100,000 US contract to an attorney for consulting work just days after Hurricane Irma brushed past Puerto Rico. It was the same attorney Ramos previously had tried to appoint as sub-director of the power company. Rossello said that contract also will be reviewed.

Ramos said in a Facebook post published on Friday before his resignation that the contract was legitimate.

"Absolutely nothing was done outside the law," he said.

PUERTO RICO Cars drive under a partially collapsed utility pole

Cars drive under a partially collapsed utility pole, after the island was hit by Hurricane Maria in September, in Naguabo, Puerto Rico, on Oct. 20.

More than 20 of Puerto Rico's 78 municipalities remain without power nearly two months after Maria hit the U.S. territory as a Category 4 hurricane. A major blackout occurred on Wednesday just as the government had announced it had reached 50 per cent of power generation. Two more large blackouts have since been reported as crews work to restore power.

Ramos said the recent blackouts were a result of problems ranging from overgrown vegetation to fuel not being supplied on time.

Rossello has said he anticipates 80 per cent power generation by end of November and 95 per cent by mid-December. However, the U.S. Corps of Engineers has said it expects 75 per cent power generation by end of January.