Worldwide personal-computer shipments fell 9.5 percent in the second quarter, hurt by restrained corporate technology spending and the strength of the U.S. dollar, market researcher Gartner Inc. said.

Manufacturers shipped 68.4 million units, compared with 75.6 million a year earlier, the steepest quarterly decline since the third quarter of 2013. U.S. unit sales fell to 15.1 million, down 5.8 percent, with desktop PCs hit particularly hard, Gartner said Thursday in a report.

The second quarter’s decline, following a 5.2 percent drop in the prior period, underscores the persistent challenges for PC makers in an increasingly mobile world dominated by smartphones and tablets. Consumers in emerging economies are buying fewer PCs, and corporations have moderated spending on technology following a slight bump in the middle of last year. PC shipments are forecast to post their fourth straight consecutive annual decline this year.

The slump last quarter took a toll on some PC-dependent companies, with microprocessor provider Advanced Micro Devices Inc. lowering its quarterly sales forecast on Monday, and memory-chip maker Micron Technologies Inc. doing the same last month. Companies such as Intel Corp. and Microsoft Corp. will release results in the coming weeks.

Lenovo Group Ltd. widened its lead as the top global supplier, with a 19.7 percent share of the market, Gartner said. The company shipped 13.5 million PCs, down 6.8 percent from a year earlier. Hewlett-Packard Co.’s shipments fell by 9.5 percent to 11.9 million, followed by Dell Inc., whose shipments shrank by 4.9 percent.