Growth in the mid-Atlantic region’s manufacturing sector stalled in December, the Federal Reserve Bank of Philadelphia said Thursday.

The Philly Fed’s survey of manufacturing businesses showed a sharp rise in the share of businesses saying their current activity contracted, from 19.9 percent in November to 29.1 percent in December. The percent of businesses seeing expansion dropped from 30.3 to 29.4.

That sets the survey’s diffusion index at 0.4 percent, down from 10.4 in November and below the 8.5 consensus forecast.

This gauge has been volatile this year. At near zero, it remains above the low hit at the start of the year.

The lower-than-expected headline score may trigger some doubts about the manufacturing recovery that was glimpsed in the Empire State survey and the surprising surge in industrial production in November.

Both the Philly Fed survey and industrial production had shown signs of a slump back in October, highlighting the volatility of the manufacturing sector as the year closes.

But silver-linings lurk beneath the headline number. For one thing, the reports of increasing activity remain strong. The reports gauges of new orders and shipments rose. Employers continued to report expanding employment.

Firms expect costs to rise next year by more than they did this year. Wages are expected to rise 2.5 percent and health care benefits costs expected to rise 4.5 percent. Nonhealth benefits are expected to rise 2.5 percent. The median total compensation cost, benefits plus wages, is forecast at 3.5 percent.

There is no sign of tariffs creating price pressure. The costs of raw materials and intermediate goods are expected to increase just 1.5 percent.

The gauge of expectations for the future nearly steady as both expectations for growth and contraction shrank, leading to a rise in the share of business saying that they expect conditions to be about the same six months from now as they are today. That broadly matches the expectations of the Federal Reserve’s policymakers and financial markets.