Google announced the sale of its Motorola Mobility unit to Chinese technology company Lenovo for $2.91 billion, a deal struck just two and a half years after it acquired the smartphone maker for $12.5 billion.

The transaction, announced on Wednesday although still subject to regulatory approval, will give Lenovo the rights to the Motorola brand and a wide range of smartphones, including the Moto X and Moto G - launched in 2013 - and the DROID Ultra series, Google said in a statement on its Web site.

The deal is being compared to Lenovo's acquisition of a unit of another iconic American brand in 2005, when it purchased IBM's struggling PC division.

Google will maintain ownership of the "vast majority" of Motorola's patents and will grant usage rights to that portfolio to the Chinese company.

"Lenovo has the expertise and track record to scale Motorola Mobility into a major player within the Android ecosystem," Google CEO Larry Page said in the press release, referring to his company's operating system for touchscreen mobile devices.

"This move will enable Google to devote our energy to driving innovation across the Android ecosystem, for the benefit of smartphone users everywhere."

Google acquired Motorola in 2011 in large part to gain ownership of its more than 17,000 patents and give itself greater leverage and protection in legal battles with competitors such as Apple.

The California-based tech giant inherited Motorola's $3 billion cash stockpile in the deal and later received $6 billion from sales of Mobile Mobility's units.

Lenovo Chairman and CEO Yang Yuanqing, for his part, hailed Wednesday's deal, saying the Chinese company would benefit from the outstanding global brand awareness Motorola enjoys.

"The acquisition of such an iconic brand, innovative product portfolio and incredibly talented global team will immediately make Lenovo a strong global competitor in smartphones," Yang said.

Motorola Mobility is currently the third-largest Android smartphone manufacturer in the United States and No. 3 manufacturer overall in Latin America.

But it has been struggling recently, including posting an operating loss of $248 million in the most recent quarter. EFE