MILWAUKEE, Wis. (AP) — Fueled by its first U.S. sales increase in more than four years, Harley-Davidson's second-quarter profit more than doubled, easily beating Wall Street's expectations.

The iconic motorcycle maker also boosted its shipment forecast for 2011 and its shares rose $1.32, or 3.2 percent, to $42.75 in premarket trading.

Harley-Davidson Inc. earned $190.6 million, or 81 cents per share, up from $71.2 million, or 30 cents per share, in the same quarter last year. The 2010 results included losses of 29 cents per share from discontinued operations.

Motorcycle and related product revenue rose 18 percent to $1.34 billion.

Analysts, on average, expected a profit of 72 cents per share on $1.26 billion in sales, according to a FactSet survey.

U.S. retail sales of new motorcycles grew 7.5 percent to 53,599 bikes, marking the company's first domestic sales increase since the fourth quarter of 2006. Globally, sales rose 5.6 percent.

Harley said it expects to ship between 228,000 and 235,000 new bikes worldwide, representing an increase of 8 percent to 12 percent over 2010 levels. The company previously said it expected to ship 215,000 to 228,000 cycles worldwide this year.