Pfizer Inc. (NYSE: PFE ) this week announced that, based on preliminary results, its previously announced offer to its shareholders to exchange all, some or none of their shares of Pfizer common stock for shares of Zoetis Inc. (NYSE: ZTS ) common stock owned by Pfizer was oversubscribed. The exchange offer expired at 12:00 midnight, New York City time, on June 21, 2013. Under the terms of the exchange offer, 0.9898 shares of Zoetis common stock will be exchanged for each share of Pfizer common stock accepted in the exchange offer.