The Gulf of Mexico should largely recover from BP's oil spill within three years, and all settlement offers to victims who lost revenue from the disaster will be based on that assessment, the administrator of the $20 billion compensation fund said Wednesday.

Attorney Kenneth Feinberg said the Gulf Coast Claims Facility used "various data and expert reports" to determine that a 30 percent recovery is likely in 2011 with full recovery in 2012. He notes, however, that the oyster business will take longer.

The fund was set up by BP PLC in August to compensate residents, fishermen and business owners for lost revenue following BP's oil well blowout off Louisiana. It has so far paid about $3.3 billion to 168,000 claimants, but many are still waiting for any money, and thousands of others claim they were shortchanged.

Feinberg has faced repeated criticism about the slow pace of payments and the small size of checks to victims.

He said Wednesday that final settlement offers, based on the recovery assessment, will be twice an individual's or business's documented 2010 losses. Oyster harvesters will be offered four times their documented 2010 losses.

Documents released by Feinberg on Wednesday show he based the assessment on expert opinions from a Texas professor and a consulting firm.

"I think I have canvassed the universe," Feinberg said. "I admit it is not certain."