Wal-Mart...has had to postpone the publication of an online report on its environmental and social sustainability efforts... Social activist shareholders have been pressing the company to follow other US corporations such as General Electric and Coca-Cola in producing a report that allows its efforts on issues such as global warming and supply chain conditions to be assessed. However, a draft presented informally to independent advisers and non-profit groups this year was rejected as inadequate. Andy Ruben, who heads the company's sustainability efforts, said the report had been delayed because of the complexities of gathering the range of data required... Separately, the retailer's efforts to work with some competitors on a new international anti-sweatshop initiative has met opposition from labour activists. Wal-Mart, Tesco, Carrefour...Metro...[and] Migros, reached agreement last year on a draft code of conduct, but labour rights and anti-sweatshop groups are concerned about their exclusion from the initial discussions...