China’s CNOOC Limited, through wholly owned finance subsidiary CNOOC Finance (2003) Limited, has offered and priced two tranches of guaranteed notes: US$200 million 4.125% guaranteed notes due 2013 and US$300 million 5.50% guaranteed notes due 2033. The 2013 Notes were priced at 77 basis points over the benchmark 10-year U.S. Treasury (with a yield of…