A recent forecast by consulting firm Deloitte predicts that retailers should expect only small gains in 2011 holiday sales, a result of the slow U.S. economic recovery.

Deloitte expects total holiday sales to reach between $873 billion and $877 billion, a 2.5 to 3 percent increase. This growth rate is smaller than last year’s 5.9 percent gain.

Gains in consumer spending “have begun to flatten,” said Deloitte’s chief economist Carl Steidtmann in a statement. “Additionally, retailers will face tougher comparisons this year after last year’s substantial increase in holiday sales.”

However, the company also predicted a 14 percent increase in non-store sales. Nearly three-quarters of non-store sales result from the online channel, with additional sales coming from catalogs and interactive TV. 

Deloitte’s forecast is slightly less than the forecast from the International Council of Shopping Centers, which predicted a 3.5 percent increase in holiday sales this season. Another company, ShopperTrak, estimated that holiday sales would rise three percent over the holiday.

JCK