OSLO (Reuters) - Scandinavian airline SAS is flying slower to save on sky-rocketing fuel costs and curb emissions of carbon dioxide in a new push to green up its image.

SAS said on Tuesday it has reduced the cruising speed of its passenger jets to about 780 kilometers (485 miles) per hour from 860 kph. The test project, run by SAS’s Norwegian unit, has saved it an estimated $12 million in fuel since early 2006.

“Our experience is that we were able to save a lot by slowing down,” said Thomas Midteide, a spokesman for SAS Norge.

“After the test project... we implemented this strategy in the (SAS) group on an everyday basis,” he added.

The move comes amidst calls by lawmakers around Europe to boost taxes on air travel as a way of combating emissions of greenhouse gasses that contribute to global warming.

A 360 km flight between Oslo and Bergen, Norway’s two largest cities, at “economy speed” saved 130 kg (287 pounds) of fuel and 420 kg of carbon emissions. The entire journey lasts only three minutes longer, Midteide said.

A slightly longer flight between Oslo and Paris or London takes about 10 minutes longer than before.

Attempting to “offset” the extra time spent in the air, SAS started early departures if all passengers were in place and on board its aircraft before the scheduled takeoff time.

Like many national flag carriers, SAS has been struggling with competitive pressure from cut-price rivals, overcapacity and, most recently, a huge rise in fuel costs.

Half owned by the governments of Sweden, Denmark and Norway, SAS was also one of the first airlines to allow passengers to pay for the carbon dioxide their plane produced.

The Oslo-Bergen flight produces some 54 kg of CO2 per passenger, which could be offset with an additional cost of 0.63 euros ($0.981) added to the ticket price, SAS’s internet booking page shows. Paying for one passenger’s share of carbon emissions on a longer flight between Oslo and San Francisco costs 7 euros.

Last month SAS said it planned to cut CO2 emissions by 20 percent by 2020 by improving energy efficiency and mixing jet fuel with renewable sources. The goal assumes 4 percent per year growth in passenger numbers for SAS during 2007-2020.

To save more fuel, SAS taxies its planes to gates on one engine, turning off the other engines after landing, Midteide said. The same tactic is planned for taxing before take-off.