Mobile phone maker Motorola Mobility is to cut 4,000 staff worldwide as part of efforts to return to profitability.

This job losses are the equivalent of 20% of its workforce, BBC reports.

The firm, bought by Google last year, said it planned to close or merge about one third of its 90 facilities which include offices and factories.

US-based Motorola also announced a shift in emphasis away from low-cost non-smartphones to "more innovative and profitable devices".

Two-thirds of the jobs will go outside of the US, Google said. It expects the cost of severance packages to be $275m.

"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," a statement said.

The firm would not comment on exactly where the jobs would be cut. It employs 250 staff in the UK at three sites; Basingstoke, Livingstone and Swindon.