The stock closed on Wednesday at 22-1/2 pence, valuing the business at 812m.

Permira bought a stake in the company in August 2005, which valued the business at £1.89 billion.

As a private company, Forbes's financial details are not known, but some in the media have valued the business at more than $1 billion.

An analysis by a money manager who is bearish on Motorola values the business at $2.50 to $3.75 a share, based on financial projections.

Over all, the deal values the business at 5.7 billion euros ($6.7 billion).

Microsoft's initial approach was pitched at $31 a share, valuing the business at $44.6bn (£22.4bn).

Analysts value the business at close to $600 million, however it is believed the Muir family will not sell for less than $1 billion.

The shares are still down from a year high of 6.3p in January to today's price of 3.75p valuing the business at £6.41m.

But, he says, it's important to have a mechanism for "valuing the business, for determining how the value would be paid."

The prospective purchaser of a country house hotel instructed a local surveyor who valued the business as a going concern at £3.75 million.