A company statement released Friday said Marrandino was "leaving Caesars Entertainment to pursue new opportunities."
The company would not specify on Tuesday whether he had resigned or was asked to step down. Marrandino did not return calls or e-mails.
The company announced that Kevin Ortzman will become general manager of Showboat, Caesars and Bally's in Atlantic City, taking over Marrandino's previous responsibilities, while John Smith will continue as GM of Harrah's Resort there.
"Throughout his career with Caesars, Don has been a great partner and contributor, displaying a dedication to service and a knack for cultivating innovative entertainment strategies," said Tom Jenkins, Caesars Entertainment's president of operations. "Since then, he has provided strong leadership in Atlantic City, playing an instrumental role in the city's initial revitalization efforts."
After Hurricane Sandy, Marrandino saw to it that Caesars employees were compensated for work days missed, held a benefit concert for them, and ensured that those who lost their homes had temporary shelter at the Claridge Hotel, which the company also owns.
A knack for booking acts that sell is what helped Marrandino, 53, land back in his native Atlantic City, where he began his career, in fall 2009.
In 21 years working the Vegas Strip, Marrandino brought Donnie and Marie Osmond to the Flamingo; the Rolling Stones, Bruce Springsteen and the Who to the Hard Rock Hotel; and Rita Rudner to Harrah's Las Vegas.
"I liken working at a casino to throwing a party every day," he said in an interview after being promoted.
But the last three years have been brutal for Atlantic City. Regional competition has eaten into the resort's gaming revenue.
In November, the latest month for which data were available, all four Harrah's Entertainment casinos reported double-digit revenue declines, ranging from 28.5 percent at Harrah's Resort to 46 percent at Bally's. December figures come out Thursday.
Across the Delaware, the renamed Harrah's Philadelphia - known as Harrah's Chester until last May - also was hurting. It reported a 3.1 percent decline in gross slot-machine revenue for 2012, and a 4.1 percent decline last month.
"Similar to other Atlantic City casino operators, the four Caesars Entertainment casinos have struggled with the onset of increased competition," said gaming analyst John Kempf, of RBC Capital Markets L.L.C.
"But Caesars has also struggled in other markets, such as Las Vegas, Louisiana, and Mississippi, which has made it difficult for the company to manage its heavy debt load," taken on following its leveraged buyout completed in 2008, Kempf said.
Contact Suzette Parmley at 215-854-2855 or firstname.lastname@example.org.