The 11 Main site is an online shopping business that offers "interesting, quality products" from "hand-picked shop owners" such as fashion, tech and jewellery goods.
Alibaba has been ramping up its international expansion with various acquisitions, including leading a roughly $200 million investment round in U.S. retail site ShopRunner Inc, setting up an investment division in the United States and offering more of its e-commerce and online payment products overseas.
At the same time China's dominant e-commerce company is gearing up for an expected public offering later this year which will value the company at around $140 billion, according to a Reuters poll of eight analysts.
The foray into boutique e-commerce was conceived and created by Vendio and Auctiva, which Alibaba.com acquired in 2010 and helped businesses sell on eBay Inc's and Amazon.com Inc's websites.
"Alibaba is happy to support 11 Main," an Alibaba spokeswoman told Reuters in an e-mail. "Alibaba is run by entrepreneurs and firmly believes in supporting entrepreneurs with great vision and a strong sense of mission for their companies."
Officials from 11 Main were not available for comment.
Alibaba was in the news earlier on Tuesday with the announcement that it had offered to buy AutoNavi in a deal valuing the Chinese digital mapping and navigation firm at $1.58 billion.
Alibaba, which already owns 28 percent of AutoNavi, has been trying to expand its product line-up to better compete with Chinese rivals Tencent Holdings Ltd and Baidu Inc.
Baidu started offering its map software for free last August, challenging AutoNavi's dominance in the Chinese navigation market. AutoNavi followed suit by offering its own navigation software for free.Get your daily dose of tech news, reviews, and insights, in under 80 characters on Gadgets 360 Turbo. Connect with fellow tech lovers on our Forum. Follow us on X, Facebook, WhatsApp, Threads and Google News for instant updates. Catch all the action on our YouTube channel.