This excerpt taken from the PFE 10-K filed Mar 1, 2007.
ITEM 5. MARKET FOR THE COMPANYS COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES
The principal market for our Common Stock is the New York Stock Exchange. Our stock is also listed on the London, Euronext and Swiss Stock Exchanges and is traded on various United States regional stock exchanges. Additional information required by this item is incorporated by reference Financial Data (Unaudited) in our 2006 Financial Report.
This table provides certain information with respect to our purchases of shares of the Companys Common Stock during the fiscal fourth quarter of 2006: