(Corrects day in first paragraph to Wednesday)

HONG KONG, Aug 22 (Reuters) - AAC Technologies Holdings Inc , an acoustic components supplier to Apple Inc , said on Wednesday quarterly net profit declined for the first time in nearly four years, bruised by a sluggish smartphone market.

Net profit in the second quarter ended June was 653 million yuan ($95 million), down 38.7 percent from a year earlier and representing the first fall since the third quarter of 2014.

Revenue slipped 14.5 percent to 3.79 billion yuan, the worst decline since 2009.

AAC, which supplies acoustic and haptic components for the iPhone, is estimated to rely on Apple for half of its revenue, according to investment research house Sanford C. Bernstein.

Its shares have slid 37.5 percent this year as trade tensions between China and the United States intensified. ($1 = 6.8740 Chinese yuan) (Reporting by Sijia Jiang; Editing by Sai Sachin Ravikumar)