May 14 (Reuters) -

A large wildfire is slowly approaching the major Canadian

oil sands city of Fort McMurray and people in four suburbs have

been told to evacuate, local officials said on Tuesday.

The fire, fueled by tinder dry conditions and high

winds, has been threatening the city in the western province of

Alberta since last week. It is now about 13 km (8 miles) away to

the south west.

Alberta Wildfire information Officer Josee St-Onge said

the blaze grew significantly on Tuesday and noted winds from the

southwest were gusting as high as 40 km/hr (24.8 mph).

"Unfortunately, these are not favorable winds for us and

the fire will continue to advance towards the town until we see

a wind shift," she told an online media briefing.

"We're seeing extreme fire behavior. Smoke columns are

developing and the skies are covered in smoke ... firefighters

have been pulled from the fire line for safety reasons."

The fire has grown in size since the last known estimate

of 9,602 hectares (37 square miles), she said.

In a statement, the local authority said residents in

the suburbs of Abasand, Beacon Hill, Prairie Creek and Grayling

had to leave by 4 pm Mountain Time (2200 GMT).

In 2016, a huge wildfire in Fort McMurray forced the

evacuation of 90,000 residents and shut in more than a million

barrels per day of oil output.

"This fire activity is very different than (in) 2016 ... We

have an abundance of resources and we are well positioned to

respond to this situation," said regional fire chief Jody Butz.

He declined to estimate how many people were impacted by

the evacuation orders. He said evacuees were encouraged to leave

Fort McMurray but could remain in other neighborhoods in the

city if they wished.

Fort McMurray is the hub for Canada's oil sands

industry, which produces roughly 3.3 million barrels per day,

two thirds of Canada's total output.

Companies including Suncor Energy ( SU ), Canadian Natural

Resources Ltd ( CNQ ) and Imperial Oil ( IMO ) have oil sands

projects within 150 kilometers of the city and many workers live

in Fort McMurray.

"This will put more people on edge, we'll have to see if

the actual production sites themselves come under threat," said

Martin King, an analyst at RBN Energy.

"Back in 2016 the fires themselves were getting close so

the companies evacuated people for safety, and of course the

people that worked in these sites were evacuated and had nowhere

to go so they ended up shutting down production."