Greenlight Capital Re Ltd. posted its third straight unprofitable quarter on losses in the investment portfolio overseen by hedge-fund manager David Einhorn.

The net loss for the period ended Sept. 30 widened to $219.7 million, or $5.98 a share, from $51.8 million, or $1.40, a year earlier, the Cayman Islands-based reinsurer said in a statement Friday.

Greenlight Re has dropped 24 percent this year in New York trading, punishing investors who looked at the reinsurer as a way to bet on Einhorn’s investing strategy. The hedge fund manager has endured losses on stocks including Consol Energy Inc. and SunEdison Inc., which were among his largest holdings at the end of June. Both dropped by more than half in the third quarter. Micron Technology Inc. also slumped.

“Our investment portfolio was adversely affected by declining prices in three of our largest investments,” Einhorn said in the statement. “With the recent market decline, we have added modestly to our net long exposure.”

Even Apple Inc., a strong performer for years, dropped 12 percent in the period.

The third-quarter net investment loss widened to $191.3 million from $54 million a year earlier. Insurance underwriting generated a loss of $27.6 million, compared with income of $4 million in last year’s third quarter.

“We are disappointed with our third-quarter results as we reported losses on both our underwriting and investment portfolios,” Chief Executive Officer Bart Hedges said in the statement, adding that Greenlight Re increased reserves on one insurance contract after a review with help from a third-party expert.

The outlook on the reinsurer was cut to negative from stable by A.M. Best., which cited “less favorable underwriting results in recent years” in a separate statement.

“Best recognizes the remediation actions taken by the company’s management and is looking for further certainty that these issues won’t detract from prospective operating performance,” the ratings firm said.

Einhorn is among U.S. money managers who set up reinsurers outside the country. The ventures can provide tax advantage and a source of funds for investing that is less vulnerable to client withdrawals. However, the influx of money managers into the industry has increased competition for insurance deals, pressuring margins. Reinsurers provide backup coverage to primary carriers.

Early Report

For the first nine months of the year, Greenlight Re has posted a net loss of $283.3 million. Results were released after the close of regular trading. The company had previously said it would report on Oct. 28. It stuck with a plan for a conference call on Oct. 29.

The reinsurer said in a regulatory filing Friday that Einhorn had taken derivative positions to guard against fluctuations on some commodities. Greenlight Re will record a gain on the contracts if natural gas prices fall or oil prices rise, according to the document.

Third Point Reinsurance Ltd., which counts on hedge fund manager Dan Loeb to run its investment portfolio, has struggled too. The Bermuda-based company has dropped 3.4 percent this year after a 22 percent slump in 2014. Third Point Re is scheduled to report third-quarter results on Nov. 3.

–With assistance from Simone Foxman in New York.