ATLANTIC CITY - Joe Domenico, the general manager of both Bally's Atlantic City and the Showboat Casino Hotel, has stepped down in what he calls a "semi-retirement" after a 31-year career in the gaming industry.

Caesars Entertainment Corp., parent company of the Bally's, Showboat, Caesars and Harrah's Resort casinos in Atlantic City, is in the process of searching for Domenico's replacement.

His departure leaves a big hole in the senior management ranks of Atlantic City's dominant casino operator. Collectively, the Caesars Entertainment properties control about 40 percent of the market. Domenico was in charge of two casinos that generated a combined $711 million in gaming revenue in 2010.

Domenico, 53, of North Wildwood, said he has no immediate plans other than to spend more time with his wife, Carol.

"It's at that point, after 31 years, that it was the right time. I had a great career with a great company," he said in an interview Monday. "You can call it a semi-retirement."

Don Marrandino, president of the Eastern Division of Caesars Entertainment, praised Domenico for his long service with the company as well as his community charity work.

"Joe has had an accomplished career with our organization," Marrandino said in a statement.