Online flash sale site Rue La La, which counts eBay as an investor, is exploring a sale that could value the company at around $400 million, people familiar with the matter said on Monday.

Boston-based Rue La La, which has attracted interest from online shopping site Gilt Groupe, has hired JPMorgan Chase & Co to advise a potential sale, the people said.

Representatives for Rue La La and Gilt Groupe did not immediately respond to requests for comment. JPMorgan declined to comment.

Founded in 2008, Rue La La was acquired for $350 million by e-commence and marketing services company GSI Commerce, which was bought three years later by eBay. EBay divested 70 percent of its Rue La La ownership into a new holding company but still retains a minority stake.

Rue La La focuses on selling high end fashion brands at big discounts to members in limited-time sales events.

So-called flash sale sites, including Gilt, ideeli, One Kings Lane and HauteLook, were especially popular during the recession, though their popularity has waned recently.

In January, Groupon Inc acquired ideeli, which had raised over $100 million in funding, for less than half of that value.

One Kings Lane, which focuses on home decor, said in June it had cut 15 percent of its workforce. Design-focused site Fab.com also announced major layoffs in May.

Analysts have pinned the sector's decline on the reduced availability of high-quality merchandise, as manufacturers have scaled back production.

A few sites still hope to buck this trend.

Gilt is planning an initial public offering for later this year, people previously told Reuters.

Zulily, an online deals site aimed at moms, initially saw its shares surge when it went public last November, but since then the shares have declined, marking a 15 percent decline for the year-to-date.