SAN FRANCISCO, March 8 (Reuters) - Online retail sales in the United States could reach $248.7 billion by 2014, growing 60 percent from 2009, according to a study released on Monday 8 March.

Driven by a 10 percent compound annual growth rate, the projected $248.7 billion is expected to account for 8 percent of total U.S. retail sales within five years, according to Forrester Research, which authored the study.

Online sales, which slowed in the downturn, have still managed to outpace sales at U.S. brick-and-mortar stores. The National Retail Federation expects 2.5 percent growth in total retail sales in 2010, well below the 11 percent online growth rate that Forrester projects -- the same as in 2009.

With more consumers comfortable with shopping online and retailers investing more in their online operations, the online sector has been steadily growing, driven by robust growth at Amazon.com Inc (AMZN.O), the industry leader.

Amazon.com posted 42 percent sales growth in its most recent fourth quarter.

Forrester expects consumer electronics and apparel, accessories and footwear to lead the growth, while sales of computer hardware and software will slow.

Still, the bulk of total computer product sales is made online. About 52 percent of computer product sales was made online in 2009, compared with 9 percent for apparel and 14 percent for electronics.

Forrester's online sales numbers do not include sales from vehicles, travel or prescription drugs.

In Western Europe, online retail sales are projected to increase by 68 percent from 68 billion euros in 2009 to 114 billion euros by 2014.

"The pan-European marketplace is still in a stage of healthy late new-market growth," wrote Forrester. (Reporting by Alexandria Sage, editing by Matthew Lewis)