A business which ensures chilled pints and mixes fizzy drinks in pubs and restaurants has been sold for £690 million to American billionaire Warren Buffett.

Engineering group IMI said it has agreed a deal to sell its beverage dispense and mechandising divisions for $1.1 billion to Marmon Group, which is owned by Mr Buffett's Berkshire Hathaway company.

The deal will see a £620m cash return to IMI shareholders. The beverage division makes cooling, mixing and dispensing systems, supplying chains such as McDonald's with soft drinks gear. The merchandising arm spans customer research and analysis, and also supplies retailers with product displays.

Together they employ about 3200 staff across the globe, including about 430 in the UK.

The dispensing arm has operations at Brighouse in West Yorkshire and Abingdon in Oxfordshire under the IMI Cornelius name, while the merchandising division includes a site at Loughborough. IMI put its merchandising division on the block in March, and today revealed it will be sold alongside the dispensing business to tighten the engineer's focus on "sweetspot" industrial markets such as supplying air conditioning systems and valves for the oil and gas industry. The drinks dispensing business has been hit by companies delaying spending on new equipment, and IMI said its revenues in the three months to the end of September were down 8% on last year.

Across the group IMI said quarterly revenues are up 4% on last year, adding it is trading in line with expectations.

IMI chief executive Martin Lamb said the sale was a "major step" for the engineer which positions the business as market-leading flow control business focused entirely on industrial-end markets.