Dell has said its computer recycling program is ahead of schedule.

Chairman Michael Dell renewed his challenge to other computer manufacturers to offer free recycling to consumers, according to a Dell statement.

Dell said it is on track to meet its goal of recovering £275 million ($550 million) of computer equipment by 2009. The company claims to have recovered more than £78 million ($160 million) of unwanted computer equipment from customers in 2006 - a 93-percent increase over 2005.

"Customers should not be forced into improper disposal due to a lack of environmentally responsible options," Michael Dell said.

Dell offers consumers free recycling of its products, without requiring them to buy new Dell products.

It has also teamed with Goodwill Industries to help consumers donate any brand of unwanted electronics at certain Goodwill sites across the US.

And with the National Cristina Foundation, Dell enables customers to donate any working computer system to non-profit organisations in the US, Canada, the UK, Ireland, France and parts of Brazil.