IBM plans to reduce its power use by about 80 percent and save $250m on electricity, support and software over five years by consolidating around 3,900 of its servers in six locations around the world

IBM said the programme will allow it to build an environmentally friendly computing infrastructure that it could then sell to customers. The initiative is part of the company's Project Big Green power consumption reduction programme, which was announced in May.

Under the project, IBM will replace 3,900 smaller servers with 30 IBM System z9 mainframes running Linux and virtualisation software. The move will cut floor space needed to house the machines by 85 percent and will conserve enough electrical power to run a small town, the company said.

IBM now has more than 8 million square feet of data centre space - the size of about 139 football fields - supporting more than 350,000 users. The company hopes that by building the energy-efficient data centres, it will encourage its business customers to follow suit.

"As one of the world's largest technology providers, IBM consistently assesses how our systems can be maximised to support our employees and clients," Mark Hennessy, vice president and CIO of IBM's Enterprise On Demand Transformation division. "A global account consolidation truly demonstrates that IBM is committed to driving stronger energy and technology optimisation - and cost savings."

The 3,900 servers that are being replaced will be recycled by IBM's recycling division.