COPENHAGEN -- The Group of 77, which represents developing countries as well as large emerging economies such as Brazil, India and China, walked out of U.N. climate-change negotiations in Copenhagen on Monday, a Brazilian diplomat said. The group walked out of the main discussion group, accusing industrialized countries of an attempt to kill the 1997 Kyoto Protocol, which mandates rich nations, but not developing countries nor the U.S., to cut greenhouse gas emissions, a person close to the talks said. Official discussions were suspended as an informal meeting was held in an attempt to solve the problem. The move was...