DUBLIN (AP) – A mammoth cloud of volcanic ash stretching 1,250 miles (2,000 kilometers) across the North Atlantic is forcing most flights between North America and Europe to divert into a sky-high traffic jam, Irish and European air authorities said.

Forecasters warned that the rapidly spreading cloud of ash from Iceland's Eyjafjallajokul volcano was projected to reach southern Greenland and the northwest tip of Spain by Saturday. The obstacle was already forcing about 600 daily flights operated by more than 40 airlines to carry extra fuel, because the diversions were lengthening flights by up to two hours.

Air safety officials stressed that the cloud does not pose any immediate threat to shut airports or ground aircraft once again. But they said the expanding obstacle would force trans-Atlantic flights into air corridors that run unusually south into Spanish airspace or north into the Arctic.

U.S. and European airlines said they were taking the latest inconveniences in stride - even though each extra hour in the Atlantic air would mean burning more than $5,000 worth of aviation fuel, or about 2,250 gallons (8,500 liters), per plane.

``We're having to fly around it like everybody else,'' Continental spokesman Andrew Ferraro said.
American Airlines spokesman Tim Smith said its trans-Atlantic flights were traveling 90 minutes to two hours longer on average. He said one flight to London's Heathrow Airport had to be canceled because it wouldn't arrive in time for the airport's overnight curfew on operations.

Delta Air Lines Inc. said its approximately 20 to 25 trans-Atlantic flights daily were arriving 30 minutes to an hour late because of the new ash diversions. Delta spokesman Anthony Black said Delta is working with other airlines to keep passengers from missing connections.

In Ireland, Aer Lingus canceled two Saturday flights to and from Boston, citing the exceptionally circuitous routes to get around the cloud, and planned to combine passengers from two flights onto one.

Ireland has borne the brunt of this week's renewed invasion of Icelandic ash into European airspace.

It shut down six western airports Friday, but rapidly reopened them all as the cloud remained sufficiently west of its Atlantic coastline.