PROVIDENCE — Newport Harbor Corp. is close to buying Hemenway’s Seafood Grill & Oyster Bar, on the ground floor of 121 South Main St., the 11-story office tower on the east bank of the Providence River.

Ken Cusson, director of restaurant operations for Newport Harbor, confirmed Thursday afternoon that the employee-owned hospitality company has the popular restaurant under agreement with Darden Restaurants Inc., of Orlando, Fla.

Hemenway’s was founded in 1985 by Edward P. “Ned” Grace III, a Rhode Islander who became a stock-market wizard and entrepreneur. Grace started the Bugaboo Creek and Capital Grille restaurant chains and owned other restaurants in the Providence area.

In 1996, Grace cashed in, selling his restaurant holdings to Longhorn Steaks Inc. for more than $57 million. He received more than $26 million, because he owned about half the stock.

LongHorn renamed itself Rare Hospitality International Inc. after the purchase, operating the Bugaboo, Capital Grille and LongHorn chains and other restaurants from its base in Atlanta. Darden acquired Rare in October 2007.

Newport-based Newport Harbor traces its roots to the 1930s. It sold its home heating-oil distribution operation in 1995 to concentrate on the hospitality business.

Newport Harbor’s employees own about half the company through an employee stock-ownership plan and the rest is held primarily by members of the company’s founding families.

It now owns and operates a number of well-known restaurants in Rhode Island, including: Castle Hill Inn & Resort, The Mooring Restaurant and 22 Bowen’s Wine Bar & Grill, all in Newport; the Waterman Grille, in Providence; Trio, in Narragansett; the Boat House, in Tiverton; the Newport Yachting Center; and Blackstone Caterers, of Middletown.

By last year, Newport Harbor had $40 million in annual revenues and employed about 1,000 full-time and part-time workers.

pgrimald@projo.com