Pfizer Inc., the world’s biggest drugmaker, took another step forward with a plan to spin off its animal health unit, registering the initial public offering with U.S. regulators

Pfizer has said it plans to sell as much as 20 percent of the new company, to be called Zoetis Inc., to raise cash. The New York-based drugmaker may enable current investors to swap a portion of their Pfizer shares for stock in the new company. Pfizer also could hold the stock for sale later.

The regulatory filing (PFE) today moves to complete the final announced piece of Chief Executive Officer Ian Read’s effort to shrink Pfizer by selling and spinning off non-drug units, which included the April sale of its infant nutrition unit for $11.9 billion to Vevey, Switzerland-based Nestle SA.

Pfizer fell less than 1 percent to $23.72 at the close of New York trading.

The animal health unit generated $4.23 billion last year from products used in livestock and pets.

JPMorgan Chase & Co. (JPM), Bank of America Corp. and Morgan Stanley (MS) are acting as underwriters.

Juan Ramon Alaix will continue as Zoetis’s CEO, and Richard Passov will carry on as Chief Financial Officer. Frank D’Amelio, Pfizer’s CFO, will be the chairman of the board of the new company.

To contact the reporter on this story: Drew Armstrong in New York at darmstrong17@bloomberg.net;

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net