Michael Gottlieb, founder of Smollensky's Restaurants, has sold a 30% stake in the business in order to fund its expansion.
The sale, for less than £1m, is to Tim and Rory McCarthy, of the McCarthy Corporation. The brothers are also partners in Mr Gottlieb's Café Spice Namaste operation in the City of London.
"The sale provides finance for expansion and for the Dover Street relaunch," Mr Gottlieb said. Smollensky's restaurant on Dover Street, in London's West End, is currently being refurbished.
Mr Gottlieb is keen to expand Smollensky's Restaurants, which currently has two sites, and open three more Café Spice operations during the course of the next two years.
"We could do plenty more, if we could find the sites," said Mr Gottlieb, who blames brewers Bass and Whitbread for hoovering up almost every available site and forcing prices sky-high.
"Restaurateurs will be forced to start thinking of other avenues if the brewers continue this rate of expansion," Mr Gottlieb said.
"Soon every high street will look the same. Planners do nothing to protect the individual operators," he added. "Customers will get bored with these concepts and tourists certainly won't come."