Encana Corp said it agreed to sell some natural gas midstream assets in Colorado for about $590 million and would likely notch more sales in Canada as it looks to cash in on the strong demand for such assets in North America.

Encana, Canada's largest gas producer, said it is on track to meet or exceed the planned sale of $1-$2 billion worth of non-core assets as it cuts back on spending to cope with weak natural gas prices.

Including the Piceance midstream asset sale, its net divestitures would stand at about $600 million so far this year, which it aims to plough back into its core business of growing natural gas and liquids production.

The Piceance basin midstream assets serve Encana's Mamm Creek, Orchard and South Parachute production and transport about 500 million cubic feet per day (mmcfd). They include about 260 miles of pipeline.

"The current highly competitive midstream environment is resulting in significant interest in our Canadian midstream assets... We are optimistic that one or more Canadian midstream divestitures will also be forthcoming by around year-end," said Chief Executive Randy Eresman.

In August, the company put its Barnett Shale natural gas assets in North Texas up for sale in an effort to bolster its financial strength amid weak natural gas prices.

U.S. gas prices have fallen about 6 percent this year and are currently at about $3.917 per million British thermal units, as supplies have surged, partly due to the advances on shale gas drilling technology.

Encana has about half of its expected daily natural gas production hedged from now through the end of 2012 at prices averaging more than $5.75 per thousand cubic feet.