Amazon.com Inc. plans to spend almost $150 billion in the coming 15 years on data centers, giving the cloud-computing giant the firepower to handle an expected explosion in demand for artificial intelligence applications and other digital services.

The spending spree is a show of force as the company looks to maintain its grip on the cloud services market, where it holds about twice the share of No. 2 player Microsoft Corp. Sales growth at Amazon Web Services slowed to a record low last year as business customers cut costs and delayed modernization projects. Now spending is starting to pick up again, and Amazon is keen to secure land and electricity for its power-hungry facilities.