Rio Tinto PLC has slapped down $87.5-million for a 9.9-per-cent stake in Vancouver-based Northern Dynasty Minerals Ltd.Rio Tinto subsidiary Kennecott Canada Inc. will pay $10 each for 87.5-million shares of Vancouver-based Northern Dynasty, which is developing the Pebble project in Alaska.

The deal with Rio Tinto, the world's second-largest miner, provides a "Good Housekeeping seal of approval" to the project, Northern Dynasty president and chief executive officer Ronald Thiessen said yesterday.

"We wanted participation on an equity level by a major as an indication of how significant this project is," Mr. Thiessen said.

Northern Dynasty describes Pebble as one of the world's largest copper-gold projects. Rio Tinto and other parties were attracted by the size of the deposit as well as its politically stable location, Mr. Thiessen said.