NEW YORK (Bloomberg) — Prices for offshore oil-rig insurance have jumped 40 percent to 50 percent after the explosion and sinking of the drilling platform in the Gulf of Mexico last month, according to one of the rig's insurers.

The accident resulted in a net loss of $5 million for Wr Berkley Corp., chairman and CEO William Berkley told reporters in New York. The Greenwich, Connecticut-based property and casualty company will continue to write the insurance, which is "a significant business", he said.

The destruction on April 20 of the Deepwater Horizon drilling rig about 40 miles off Louisiana's coast left 11 of the 126-member crew dead and caused a leak that has poured millions of gallons of oil into the Gulf and soiled at least 70 miles of coastline. BP Plc, the biggest oil producer in the Gulf of Mexico, leased the rig from Transocean Ltd. and is seeking to plug the leak.

"We would write the exposure again," said president and chief operating officer Rob Berkley, who is William Berkley's son. "We would write it again at the rate that we charged, but we will write it again more happily at a 40 percent increase."

The amount of insurance required for offshore drilling rigs may also increase, making the accident "a good opportunity for us", William Berkley said.