Trillium Asset Management, the $750m (€806m) US fund manager, has joined a coalition of shareholders calling on BP Amoco to report on the impact of oil and gas drilling on the coastal plain of the Arctic.

The campaign is being led by US Public Interest Research Group (Pirg), the national state lobbying service. It is backed by Trillium, Boston-based Walden Asset Management, the World Wildlife Fund and the Green Century Balanced Fund. Trillium alone holds more than $5m worth of BP Amoco stock.