The company, which made the move last week as part of its 2007 Global Citizenship Report, hopes that the disclosure will encourage greater accountability and transparency across its supply chain.

The move is the latest in a line of initiatives from HP designed to limit the environmental impact of its supply chain as it seeks to meet its target of slashing emissions from its operations and products by 20 per cent by 2010. The company has been undertaking a wide-reaching programme of supplier engagement designed to encourage its partners to implement environmental strategies and earlier this year released a set of green supply chain guidelines designed to help other multinationals better monitor and manage their smaller suppliers.

However, despite progress in improving the performance of some its suppliers, the report also raised worrying issues regarding the CSR performance of many others in its supply chain.

According to the report's supply chain audit, up to half of the sites in HP's supply chain employing 400,000 people or more failed to conform to the Electronic Industry Code of Conduct's guidelines on working hours, while up to a quarter failed to comply with wages and benefits guidelines, and a similar number didn't meet health and safety guidelines.

Despite these issues, Sarah Westervelt, eWaste product co-ordinator for the Basel Action Network, a pressure group dedicated to monitoring contraventions of the Basel Treaty on hazardous waste, was encouraged by the results. "Kudos to HP for leading the way by naming their suppliers," she said.

However, she added that the company should now extend its disclosure policy to cover the entire lifecycle of its products and release information on its recycling partners as well.

"Now, customers should expect to see similar transparency regarding HP's recycling vendors, and a public commitment to respect the Basel Convention for all their exports, in every country in which they do business," she said. The convention, which entered into force in 1992, restricts the use of hazardous waste, but the US failed to ratify the agreement.

HP commissioned ERM, a global environmental consulting firm, to track end-of-life product handling. The consultancy found that HP was only able to audit the first tier of recycling companies, and could not see what happened to the products after they left the hands of first-tier recyclers. "That's irresponsible," Westervelt said. "They need to be tracking materials through final deposition, and it's very possible to do that. "

Meanwhile, the race to be seen as the greenest IT company stepped up a gear last week after Dell, the self-styled greenest IT company, announced that its Austin, Texas headquarters is now 100 per cent powered by non-fossil fuel energy. The company said the site now gets 40 per cent of its energy from Waste Management, a local company producing power from landfill, and the remaining 60 per cent from wind turbines.