HANGZHOU, China — Alibaba Group Holding Ltd., China's biggest e-commerce company that held its initial public offering last year, bought a more than $56 million stake in U.S. online retailer Zulily Inc., according to a regulatory filing.

The purchase of $56.2 million shares in the Seattle-based company comes as Alibaba announced a 45 percent increase in revenue, according to a separate regulatory filing May 7. The company also said Daniel Zhang will become its chief executive officer May 10, replacing Jonathan Lu, who will remain on the board as vice chairman.

The Zulily stake is the latest move by Alibaba, which has announced at least $2.4 billion in investments in the past 12 months including a Chinese soccer team, a smartphone maker and a mobile application for hailing taxis.

The company is trying to diversify while still tapping the more than 557 million Chinese who access the Internet from their smartphones and tablets.

Alibaba’s Zulily stake was previously reported by the Wall Street Journal. Zulily focuses on selling clothing, home decor and related items, mostly to women.

By Kristen Haunss, with assistance from Lulu Yilun Chen, Tim Culpan, Suresh Seshadri. Editors: Shannon D. Harrington, Brendan Murray, Ros Krasny.