March 12 (Bloomberg) — Exchange-traded funds focused on China are posting the world's biggest outflows amid concern economic growth is slowing.

Withdrawals from U.S.-based Chinese ETFs totaled $87.5 million March 10, the most among 46 nations, bringing this year's redemption to $380.7 million, according to data compiled by Bloomberg. The iShares China Large-Cap ETF, the largest Chinese exchange-traded fund in the U.S., fell 1.6 percent to $33.90 yesterday. The Bloomberg China-US Equity Index of the most-traded stocks in the U.S. dropped 2 percent to 99.60, led by Vipshop Holdings Ltd.

Official data over the weekend showed the steepest slide in exports since 2009 and the slowest inflation in 13 months, highlighting the challenges for Premier Li Keqiang in achieving this year's economic-growth target of 7.5 percent. China had its first onshore bond default after Shanghai Chaori Solar Energy Science & Technology Co., a solar-panel maker, said last week it would fail to pay interest on notes due March 2017.