British pharmaceutical company AstraZeneca on Thursday said it was cutting 2,300 jobs on top of the 1,600 losses it announced at the start of the week, in a major restructuring of the group over the next three years.

The company said 2,300 posts would go as it makes changes to its Selling, General and Administrative operations -- which encompasses corporate and support functions.

"We are combining this SG&A restructuring with two previously announced programmes. These comprise the headcount reduction of 1,600... announced on 18 March 2013, and the balance of the Phase 3 restructuring programme announced in February 2012, which amounts to 1,150 roles."

It added in a statement: "The total combined Phase 4 programme entails an estimated global headcount reduction of about 5,050 over the 2013-2016 period."

AstraZeneca currently employs about 57,000 staff worldwide