Blatstein bought the former Atlantic City casino and reopened it this year as a non-gambling hotel. He told The Associated Press that Icahn, who owns the Trump Taj Mahal casino next door, agreed to only "a minor consideration" that does not involve payment in return for resolving the claim.
At issue was a 1988 legal covenant requiring that the Showboat not be used for anything other than a casino. That document scuttled Stockton University's attempt to turn the casino into a satellite campus after buying it without getting the restriction lifted.
The university then sold the casino to Blatstein, who is mulling plans unlikely to include casino gambling.
"I have a nice working relationship with Carl, and he is interested in doing the right thing for Atlantic City," Blatstein said. "No money changed hands, and it was a pleasure dealing with him."
A spokesman for Icahn confirmed the agreement but declined to comment further.