The deal will see all its non-BBC branded magazines, including the Radio Times, handed over to Exponent, owner of online media jobs service Gorkana.
It has also bought the rights to publish BBC branded titles such as Top Gear.
Exponent emerged as the preferred bidder in May.
The company has also taken over BBC Worldwide’s 50% stake in Dovetail, its subscription fulfilment service, which it runs in partnership with Dennis Publishing. It has also bought its stake in distribution company Frontline.
BBC Worldwide CEO John Smith said the deal will allow BBC Worldwide to concentrate on expanding its digital services.
“The deal announced today offers the best prospects for the magazines business to continue on this path of success, while BBC Worldwide pursues a strategy increasingly focused on international video and digital services,” said Smith.
“The consumer magazines market faces a number of challenges, and this transaction brings a focus and degree of investment that BBC Worldwide alone is unable to provide.”
BBC Magazines staff and operations will be moved over to the new company on completion this autumn.
The news comes as BBC Magazines prepares to ramp up its digital strategy across its portfolio. Last week it launched its first subscription-based iPad version of its Good Food magazine – the first of a series of steps toward the roll-out of iPad versions of all its titles.