China Development Bank (CDB) started marketing its US$1 billion equivalent bond in Singapore, laying the ground for a sovereign issue next month that could raise as much as US$2 billion. The senior unsecured CDB issue will be split into a US dollar 10-year tranche and a long, euro-denominated, five-year tranche, maturing in 2010, sources said. Exactly how big each of those tranches would be in the end depends on demand. The issue is rated A2 by Moody's Investors Service, A-minus by Fitch Ratings.