Alibaba's U.S. shares dropped 4% in premarket trading Thursday after the Chinese tech giant posted net income that plummeted 75% in the June quarter.

The company has been investing heavily in AI infrastructure. The spending has weighed on its results, with capital expenditure up 75% to 67.7 billion Chinese yuan.

The jump in spending was due to uneven timing of customer purchases, an increase in CPU-compute capacity and higher prices across a broad range of chip components, the company said.

Revenue at the tech giant's key cloud division totaled 48.4 billion yuan, up 45% year-on-year. Alibaba's cloud unit is seen as key to the company monetizing artificial intelligence, much like Microsoft or Google.

U.S. listed shares were last trading down 4.11%.

This is breaking news. Please refresh for updates.