Alliance Boots stepped up its acquisition spree today, taking a controlling stake in high street optician Dollond & Aitchison.

It will merge the company with its Boots Opticians brand to create the second-biggest optical chain in the UK and a serious rival to the market leader Specsavers.

The combined firm will have 690 practices employing more than 5000 people and sales of around £350 million a year.

Neither side would give the terms of the deal, suggesting that Dollond & Aitchison was sold for a nominal sum. Its name will disappear as the stores come under the Boots name.

D&A was set up by De Rigo, an Italian firm owned by two brothers, Ennio and Safilo De Rigo. They will retain a stake in the company. De Rigo is best known for luxury sunglass names such as Luxottica and Safilo.

Stefano Pessina, the private-equity king who bought Boots last year, has been snapping up chemists and other businesses across Europe as part of bold plans to grow the business.

Pessina said: “The merger gives us an excellent opportunity to create a leading force in the UK optical market. Our plan is to grow and develop the new business, building on the strengths of the Boots brand.”

UniCredit Markets & Investment Banking acted as the financial adviser to Alliance Boots.

Pessina and private-equity house KKR paid £12 billion for Boots, Europe's biggest leveraged buyout.