India's Zetwerk is preparing to confidentially file draft papers for an initial public offering within the next one to two weeks, aiming to raise up to $550 million at a valuation of about $4 billion, according to two people with direct knowledge.The ?contract electronics manufacturer's ?IPO ?includes about $300 million in fresh equity, with the remainder coming from an offer for sale, the sources said.Zetwerk is targeting a listing later this year and has mandated Kotak as lead banker, alongside Morgan Stanley, Goldman Sachs, Pantomath Capital Advisors, JM Financial and HSBC, the sources said.Zetwerk declined to comment, while the banks…