US stocks set for another big fall after Apple's warning

Apple's shock warning that its Chinese sales are weakening ratcheted up concerns about the world's second largest economy and weighed heavily on global stock markets as well as the dollar on Thursday.

In a letter to shareholders on Wednesday, Apple CEO Tim Cook said iPhone demand was waning in China and would hurt revenue for the October-December quarter.

In the letter, which was released after the markets closed, Cook said Apple expects revenue of USD 84 billion for the quarter, almost a tenth lower than the consensus expectation in financial markets.

Apple's warning, its first since 2002, deepened concerns about the Chinese economy, which had been showing signs of stress amid a trade war with the United States.

Shares in the company fell 7.6 per cent to USD 146 in after-hours trading and US stock markets were poised for further big falls at the open.

Dow futures and the broader S&P 500 futures were down 1.4 per cent.

Europe suffered similar declines, with Germany's DAX down 1.3 per cent at 10,451 and France's CAC 40 declining 1.2 per cent to 4,636. Britain's FTSE 100 was 0.4 per cent lower at 6,709.

"For a while now there's been an adage in the markets that as long as Apple was doing fine, everyone else would be OK," said Neil Wilson, chief markets analyst at Markets.com.

"Therefore, Apple's rare profit warning is a red flag for market watchers. The question is to what extent this is more Apple-specific, or more macro?"