HONG KONG, Jan 6 (Reuters) - Reliance Industries Ltd (RELI.NS) has raised $4 billion in a three-tranche U.S. dollar bond issuance, according to a term sheet seen by Reuters. The Indian conglomerate raised $1.5 billion in a 10-year tranche, $1.75 billion in a 30-year and $750 million in a 40-year deal." Part of the cash will be used to refinance $1.5 billion worth of debt due to mature in February, the term sheet said. Reliance did not immediately respond to a request for comment from Reuters. Reporting by Scott Murdoch; Editing by Muralikumar Anantharaman