The Aga, beloved icon of the British middle class, has become the unlikely centre of a takeover tussle between two US appliances giants.

The cooker, costing as much as £16,000 , is produced by Aga Rangemaster, which said on Tuesday it received a bid proposal from Whirlpool, countering an agreed £129 million offer from Middleby Corp.

The bidders are tussling for control of a brand that has come a long way since the days when its purpose was just as much to heat country cottages as it was to do the cooking.

Although still keeping their traditional sturdy appearance, the stoves have been equipped with technology that has made them a popular addition to the modern kitchen.

Owners include UK prime minister David Cameron and actress Sharon Stone. "It's an aspirational brand, that's its key appeal," said Matthew McEachran, an analyst at N+1 Singer. "Aga ovens are no longer less efficient than rivals."

Much about the Aga hasn't changed since it was invented by Swedish Nobel Prize-winning physicist Gustaf Dalen in 1922.

What has changed is the gadgetry inside. Originally designed to radiate heat all day, the multiple ovens within an Aga can now be controlled individually. In some models, owners can also use a smartphone to turn compartments on or off.

Becoming part of a larger company would give the brand the resources needed to further that innovation and penetrate new markets – something it has struggled to do as pension liabilities have thwarted Aga Rangemaster’s growth ambitions.

That’s where Middleby and Whirlpool come in. Middleby plans to put Aga alongside its Viking ovens, saying the brand fits its strategy of expanding globally, and will strengthen its position as a leader in premium products.

First it will have to fight off Whirlpool, which said on Tuesday that it approached the Aga board regarding a possible offer. Aga shares rose 14 per cent to 209.75 pence in London, exceeding Middleby’s 185 pence cash offer.

- Bloomberg