The company, which is over 100 years old, has instructed property firm Colliers International to search for sites in the West End.
It is also targeting other high-footfall locations including Covent Garden, Oxford Circus, Waterloo and Piccadilly.
Balls Brothers is seeking units ranging from 4,500 sq ft, in close proximity to office developments.
The nine-strong group was bought out of administration by Novus Leisure in 2011, which undertook a revamp of its sites.
“After completing a number of refurbishments from within our existing estate we are excited about the opportunity to add new properties to our portfolio in both the City of London and the West End,” says Toby Smith, CEO of Novus Leisure.
Novus operates 43 restaurants, bars and late-night venues in London, including the Tiger Tiger brand.
The group bought three Rocket Restaurants sites in January for an undisclosed sum.