Rumours of a possible marriage between Buffett and Heidelberg began earlier this month when Buffet revealed he was keen to buy family-owned German businesses.

He said: "We would like more family owners of German businesses, when they feel some need to monetise their businesses, to think of Berkshire Hathaway.

"We're looking for companies that have at least $50m (£25.2m) to $75m in pre-tax profit. The bigger the better."

Buffett's stated desire for long-term investments in durable, competitive businesses with qualified management in place and the potential for a good return, could make Heidelberg a prime target.

However, chief executive Bernhard Schreier was quick to deny any contact with Buffett: "I don't even have an appointment with him."

Schreier also stressed that Heidelberg's major shareholders, including RWE and Allianz, had not made any comments indicating to Buffett that they were interested in selling their stakes.

Nevertheless, Heidelberg's shares jumped following Buffett's comments, while further speculation was sparked by Berkshire Hathaway vice chairman Charlie Munger, who praised Germany's engineering prowess and said: "It's a very logical place for us to be looking."