In what appears to be a surprise move, Peter Lankau has resigned as ceo, president and board member to “pursue other interests,” the specialty pharma says in a statement. He leaves on March 1.

Nancy Wysenski, Endo’s chief operating officer, and Charles Rowland, Jr., Endo’s executive vp and chief financial officer, will assume day-to-day responsibilities until a successor is appointed. Wysenski will also be coordinating responsibilities of the other members of the senior executive team. The board has hired Russell Reynolds to conduct a search for a new ceo.

Roger Kimmel, Chairman of the Board, and two other independent directors, George Horner, III and Clive Meanwell, will “liaison” with Wysenski and Rowland until a new ceo is found. Kimmel says: “We appreciate the contributions Peter has made to the growth of the company over the past seven and a half years. We wish him well.” Meanwhile, Rowland adds that Endo should meet “or exceed” earnings guidance for 2007.

UPDATE: In an investor note Tuesday morning, Jeff Englander, a healthcare analyst at Standard & Poor’s, writes: “We think the Endo board had become frustrated at the pace of execution on the company’s strategic plan, notably with respect to acquisitions reducing Endp’s dependence on Lidoderm and Opana revenues. We do not believe issues relate to (fourth quarter) or 2007 (earnings per share).”