Samsung expects its quarterly operating profit to fall 29 per cent compared with last year, potentially unsettling a tech sector already skittish about slowing global economic growth.

The announcement from the South Korean computer chip and smartphone giant comes less than a week after a weak outlook from Apple Inc jolted markets.

Samsung said late Monday that it anticipates a quarterly operating profit of about 10.8 trillion won ($9.6 billion). It expects fourth-quarter sales to drop almost 11 per cent from a year ago, to 59 trillion won ($52.4 billion).

Samsung said there's weak global demand for chips amid a worldwide economic slowdown, while its smartphones are facing stronger competition.

In a rare move for Apple, the company walked back its sales expectations for the last quarter of 2018, citing flagging sales in China . Its earnings report is due on Jan 29.

China is a huge smartphone market, accounting for one-third of the world's handset shipments, but its economy has been slowing and many people are leery of the rising trade tensions with the US. They have also begun to buy smartphones from Chinese manufacturers such as Huawei and Xiaomi. Many models are cheaper than those made by Apple and Samsung.

Tech companies are not alone in feeling the slowdown in China. Companies ranging from Tiffany & Co to Ford Motor Co have also warned of sales declines.