The company, run by Steve Ball and Riz Shaikh, has spent 1.43m acquiring the leases of the two new venues and is hoping to integrate them into its existing estate, which includes Paradise by Way of Kensal Green and The Blues Kitchen in Camden.
Popular Broadway Market 'boozer' The Cat and Mutton will be run in partnership with Tom Gibson, owner of Ruby's Cocktail Bar in Dalston and has closed for refurbishment while improvements are made to the two-storey building. It will re-open in March with a new look, but its name will remain.
Work has also started to turn converted Victorian warehouse Bar Music Hall, formerly known as Brick Lane Music Hall, into Blues Kitchen Shoreditch. Ball said it would become as East London sibling to the original Blues Kitchen in Camden, which opened in 2009.
The new Blues Kitchen will include a spacious diner serving Texan barbecue, and its bar will offer one of the biggest bourbon selections in London. Live music will also be performed seven nights a week.
Ball said: "The opportunity to take on these two classic East London venues was too great to pass up. They’re both superb sites with great potential and a strong local story behind them."
"We are very excited about growing The Columbo Group’s East London presence and introducing the Blues Kitchen concept to a new audience on the Bar Music Hall site.”
Ball said there was potential to expand The Blues Kitchen brand further in the future as it had been well-received in Camden, but that it would be done on a small scale if it did.
"We hope to expand the Blues Kitchen business while maintaining its integrity and spirit," he said. "I imagine at some point in the future there may well be a third Blues Kitchen but I think the phrase 'roll out' might be a bit strong."
Ball and Shaikh formed The Columbo Group in 2006, taking on the Old Queens Head in Islington and Paradise By Way of Kensal Green. The pair went on to open Blues Kitchen in Camden, XOYO in Shoreditch, Love & Liquor in Kilburn and The Nest in Dalston in 2010.
The group now has an annual turnover of £18m and employs approximately 300 people.