Xcel Energy on Friday said customers' natural gas bills in March are expected to decline 19 to 21 percent from this month and also March 2008 because of falling gas prices and lower consumption.

Xcel asked the Colorado Public Utilities Commission for permission to decrease gas prices for residential and small-business customers by 8 percent next month from this month's price.

Residential bills would decrease to $69.67 from $86.19 this month. Typical March 2008 bills were $88.28. Typical small-business customer bills would decrease to $334.54 from this month's $416.27. Typical March 2008 bills were $419.44.