Internet giant Google has announced a deal to buy Motorola Mobility for $12.5bn (£7.7bn).
A joint statement said the boards of both companies had unanimously approved the deal, which should be completed by the end of this year, or early in 2012.
Earlier this year, Motorola split into two separate companies.
Mobility develops and manufactures mobile phones, while Motorola Solutions covers wider technologies for corporate customers and governments.
The price of $12.5bn, or $40 per share, represents a 63% premium on the closing share price of Motorola Mobility on Friday, the joint statement said.
The deal would allow Google to "supercharge" its Android operating system, the company said.
It added that it would continue to run Mobility as a separate business.
'New opportunities'
"Motorola Mobility's total commitment to Android has created a natural fit for our two companies," said Larry Page, Google's chief executive.
Sanjay Jha, his counterpart at Mobility, said: "This transaction offers significant value for [our] stockholders and provides compelling new opportunities for our employees, customers and partners around the world."
The deal is subject to shareholder and regulatory approval.
Motorola was once one of the world's most successful mobile phone manufacturers, but has fallen behind the likes of Apple, Samsung and HTC in recent years.
Many of its handsets already use Google's Android operating system.
They didn't buy Motorola in order to just make phones - that is not their immediate incentive. See 