Pfizer announced a $5 billion accelerated buyback

(Reuters) - Drugmaker Pfizer (PFE) said it entered into an agreement with Goldman, Sachs & Co to buy back $5 billion of its stock.

Pfizer said the accelerated share repurchase was assumed in the forecast for the full year it provided last month.

Under the agreement, which forms a part of Pfizer's existing buyback authorization, about 150 million shares will be bought.

The settlement is expected during or prior to the third quarter.