( AMZN - Get Report)acquired, a retailer of women's apparel and accessories, as the largest Internet retailer looks to lure more shoppers to its Web site.

Shopbop will operate as a stand-alone Web site and will continue to be run from its headquarters in Madison, Wis., with its existing management team. Terms were not disclosed.

The acquisition will complement Amazon's fashion line, which already features designers such as Calvin Klein, Armani, Gucci and Versace. Shopbop was founded in 1999 as a bricks-and-mortar store and carries lines from 75 designers including Marc Jacobs, Juicy Couture and True Religion.

Wall Street remains pessimistic about the prospects of Seattle-based Amazon, because the company faces rising competition from huge rivals including Wal-Mart ( WMT - Get Report). Investors also are skeptical of Amazon's reported interest in developing a rival digital music service to Apple's ( APPL) iTunes.

Online consumers are becoming more price-conscious than ever, thanks to comparison shopping engines, which are squeezing the margins of Amazon. Last month, the company reported disappointing fourth-quarter profit as operating expenses rose at a faster rate than sales.