Google will cut 20% of jobs at Motorola Mobility, the mobile device maker it acquired for $12.5 billion last year.

Around 4,000 roles will be axed as Google restructures the company to reflect new strategic priorities. Motorola Mobility will withdraw from unprofitable markets, discontinue low-value devices and simplify its product suite.

"Today, Motorola Mobility announced that it’s reducing its headcount by approximately 4,000," the company said in a statement today. "Motorola plans to close or consolidate about one-third of its 90 facilities as well as simplify its mobile product portfolio – shifting the emphasis from feature phones to more innovative and profitable devices."

"While Motorola expects this strategy to create new opportunities and help return its mobile devices unit to profitability, it understands how hard these changes will be for the employees concerned," the statement continued. "Motorola is committed to helping them through this difficult transition and will be providing generous severance packages, as well as outplacement services to help people find new jobs."  

Google’s acquisition of Motorola Mobility had been seen largely as a defensive move, giving the web giant a treasure trove of mobile technology patents with which to protect itself in an increasingly combative mobile.

However, in an interview with the New York Times today, Motorola Mobility CEO David Woodside said the acquisition was critical to understanding how consumers use mobile devices – critical for Google’s long term survival.

“We’re excited about the smartphone business,” Woodside told the newspaper. “The Google business is built on a wired model, and as the world moves to a pretty much completely wireless model over time, it’s really going to be important for Google to understand everything about the mobile consumer.”

Motorola Mobility had already standardised on Google’s Android operating system for its smartphones by the time it was acquired. When the acquisition gained regulatory approval earlier this year, Google CEO and co-founder Larry Page said he expected Motorola to produce ""the next generation of mobile devices that will improve lives for years to come".

However, Google’s recently launched Nexus 7 tablet, arguably its most significant own-brand hardware offering to date, is built by Taiwanese manufacturer Asus.