The Mekong River Commission, composed of Cambodia, Laos, Thailand and Vietnam, delayed the construction of a major dam project on the Mekong River for the second time this year on Thursday . . . the $3.5 billion 1,260 megawatt Xayaburi dam project was delayed so Japan can finish an environmental impact study . . . the project was to be built by Thai companies and would provide 95 percent of the electricity to Thailand . . . Cambodia and Vietnam called for the additional delay to the project . . . last week an international petition composed of more than 100 countries called on Laos and Thailand to cancel the project . . . the delay is a major setback for Laos, which is trying to reinvent itself as the hydropower “battery of Southeast Asia” . . . the dam is an attempt by Vientiane to help reduce its rampant poverty, as over one quarter of the people in Laos live beneath the poverty line.