SYDNEY (REUTERS) - Sydney Airport resumed normal operations on Saturday (Nov 24) as strong winds that caused airline chaos a day earlier eased, a spokesman said.

Winds gusting up to 70kmh caused Sydney Airport to close one runway on Friday, leaving international and domestic travellers stranded in Australia's most populous state.

Sydney Airport cancelled 76 flights after all but one runway was closed.

Weather bureau meteorologist Rosemary Barr told Reuters the winds gradually eased on Saturday to up to 30kmh after a low-pressure system in the Tasman sea weakened and moved east.

The winds had been part of a massive weather system over south-east Australia that whipped up a 500km dust storm on Thursday, which swept across the drought-parched interior to blanket Sydney.

Sydney Airport spokesman Cait Tynan said the airport was operating normally on Saturday, with both runways operational.

Virgin and Qantas airlines put on additional flights to clear the backlog of travellers stranded by the weather.

Jetstar Airways said it had seven cancellations early on Saturday morning but was back on schedule by noon.

The easing winds also brought relief on Saturday after 21 fires were fanned by the strong gusts across New South Wales state on Friday.

A modified Boeing 737 capable of carrying 15,000 litres of water or fire retardant helped to fight fires around the city of Newcastle, north of Sydney, on Friday.

More than 100 firefighters prepared containment lines in the area overnight, the Rural Fire Service said.