WASHINGTON – Orders to U.S. factories rose in October by the largest amount in 16 months but a key category that tracks business investment posted an anemic gain.

The Commerce Department says factory orders increased 2.7 percent in October, the best showing since a 2.9 percent rise in June 2015. The strength came from a big 93.8 percent surge in the volatile category of commercial aircraft. A category that serves as a proxy for business investment edged up just 0.2 percent following a 1.5 percent drop in September.

U.S. manufacturers have struggled for much of this year, having to deal with the impact of a strong dollar, which makes their exports more expensive in overseas markets, and big cutbacks in investment spending by energy companies in the wake of falling oil prices.