People walk past a logo next to the main entrance of the Google building in Zurich
People walk past a logo next to the main entrance of the Google building in Zurich March 9, 2011. REUTERS

Google Inc said it will buy phone hardware maker Motorola Mobility Holdings Inc for $12.5 billion in cash to bolster the adoption of its Android mobile software.

In its biggest deal to date, Google said it would pay $40 per share, a 63 percent premium to Motorola Mobility's Friday closing price on the New York Stock Exchange.

"What it says is that Google wants to provide a total experience that's hardware and software (like Apple)," said BGC Partners analyst Colin Gillis.

Shares of Motorola Mobility, which focuses on smartphone and TV set-top boxes, jumped 59 percent in premarket trade on Monday.

Google, maker of the Android mobile phone operating system software, has been forging ahead in the smartphone market but has been hampered by a lack of intellectual property in wireless telephony.

Earlier this month, fresh from losing a bid to buy thousands of patents from bankrupt Nortel, Google Chief Legal Officer David Drummond blasted Microsoft, Apple, Oracle and "other companies," accusing them of colluding to hamper the increasingly popular Android software by buying up patents.

The Motorola Mobility deal may represent a victory for activist investor Carl Icahn, Motorola's biggest shareholder. He has urged Motorola to consider splitting off its patent portfolio to cash in on surging interest in wireless technology. As of July, Icahn held an 11.36 percent stake in the company.

Google said the deal will close by the end of 2011 or early in 2012 and that it will run Motorola Mobility as a separate business.

Lazard advised Google on the deal, while Motorola used Centerview Partners and Frank Quattrone's Qatalyst Partners, sources told Reuters.