Zynga Inc., the biggest maker of online social games, said it will cut 520 jobs, or 18 per cent of its staff, and close some offices amid disappointing results from its titles outside the Farmville series, Bloomberg reported.

The reductions will save an estimated $70-80 million in pre-tax expenses annually, the San Francisco-based company said on Monday in a statement. The cuts will be completed by August, and will result in restructuring charges of $24-26 million in the second quarter and $2-5 million in the third quarter.

Zynga will also record about a $15 million reversal of stock-based expenses because of the job reduction, and said the net loss in the current period will be between $28.5 million and $39 million, including the costs of the restructuring.