Royal Dutch Shell has abandoned its search for oil in the Arctic after failing to find enough supplies of crude.

It has reportedly spent $7 billion (6.26 billion euros) exploring the waters off Alaska and says the cost of pulling out for the foreseeable future could be $4.1 billion (3.67 billion euros).

The company cited its reasons in a statement: insufficient supplies, the project’s high costs and unpredictable US federal regulations. Shareholders had also put pressure on Shell to stop.

Environmental campaigners have long argued that drilling for oil threatened the region and its wildlife, and have welcomed the withdrawal as a watershed moment for the climate.

Greenpeace described the end of the drilling programme as a defining day for the Arctic.

BREAKING: US$7bil & 7 yrs later Shell ceases Alaska drilling #ShellNo #savethearctic http://t.co/jOf2UPX0L6 pic.twitter.com/01wJJhzy14— Greenpeace (Greenpeace) September 28, 2015