DALLAS - Hurricane Rita may have caused more damage to rigs and platforms than any Gulf of Mexico storm — even its formidable predecessor Hurricane Katrina, oil and gas analysts said on Wednesday.

The double-whammy of those hurricanes has already cost the Gulf almost 7 percent of its annual oil production and 5 percent of its yearly natural gas output, according to a report Wednesday from the U.S. Minerals Management Service.

“The impact on the rigs is something that’s never been seen by this country before,” said Daniel Naatz, director of federal resources for the Independent Petroleum Association of America.

ODS-Petrodata, which provides data and information to the industry, reported 13 rigs already seriously damaged or destroyed by Rita. Platform damage still is being assessed, said Tom Marsh, ODS analyst

“You may think that 13 is not significant amount, but this is 10 percent of the contracted fleet out of service for various lengths of time or in some cases permanently,” Marsh said.