Bloomberg reports that Pfizer Inc.’s former chairman and CEO William Steere is retiring from the board after building the world’s biggest drugmaker with acquisitions and products led by the Lipitor cholesterol pill. Steere, 74, was CEO of New York-based Pfizer from 1991 to 2000 and chairman from 1992 to 2001. Steere is under a five-year contract for consulting services to Pfizer through mid-2011. The agreement will automatically renew for five years unless Steere or Pfizer ends the arrangement. Steere orchestrated the $87 billion acquisition of Warner- Lambert in 2000, the biggest deal in the company’s history, which about doubled Pfizer’s market value. In the purchase, Pfizer got Lipitor, the world’s best-selling drug with top sales of $12.89 billion in 2006. Pfizer’s shares have declined 59 percent since their peak soon after the deal.