Sir Alan has branched out from his roots in electronics

It has been a core part of Sir Alan's business empire and has employed the winners of BBC's The Apprentice prime-time reality TV show.

So does the deal spell the end of Amstrad?

The Brentwood, Essex-based company will be owned by Sky, but Sir Alan will continue to run it for the time being.

Sir Alan explained: "It's not a case of letting it go, it's a case of moving the company on to something more positive.

"The good news for my employees is that they've now got a secure future with great opportunities," he told the BBC.

"The bad news is that I'm still going to be around for a while, so nothing changes at Amstrad."

So is Sky getting a good deal?

On the whole, analysts have backed Sky's move, saying it would help them gain a technological edge over their rivals.

Amstrad makes the decoder boxes that come with satellite TV systems and supplies about 30% of those used by Sky customers. Sky accounts for about 75% of Amstrad's annual sales.

Owning the company will allow Sky to have a greater say in how the decoder boxes are made, getting them tailored more specifically to their requirements.

Will Sir Alan have to find new business ventures?

He has been diversifying for a number of years already.

Simon Ambrose is the only Apprentice still working for Sir Alan

A lot of Sir Alan's wealth - which is estimated at �830m, placing him as the 84th richest man in the UK - is tied up in property, and is controlled by the Amsprop investment company run by his son Daniel.

He also owns the aviation firm Amsair, which charters planes for businesses and private travellers.

But where will the winners of The Apprentice work?

Well, the first two winners have already cut and run, but Simon Ambrose, the latest successful candidate, has started at Amsprop.

According to press reports, Mr Ambrose and Sir Alan are planning on building London's most expensive office and may bid for a prime site on London's St James's square.