Wal-Mart, the US retailer, yesterday announced a $35m programme aimed at preserving natural habitats that represents one of its largest commitments to an individual national organisation.

The company, seeking to improve its image amid criticism of its employment and social policies, said it would provide the money over 10 years to the National Fish and Wildlife Foundation to fund the conservation of one acre of "priority wildlife habitat" for every acre covered by Wal-Mart's present and future facilities.