OMAHA, Neb. — A January survey of business supply managers is signaling solid economic growth over the next three to six months for nine Midwestern and Plains states despite a slight decline in business confidence, according a report issued Friday.

The Mid-America Business Conditions Index rose to 56.0 last month from 55.2 in December, the report said. The November figure was 54.1.

“The regional economy continues to expand at a positive pace,” said Creighton University economist Ernie Goss, who oversees the survey. “However, as in recent months, shortages of skilled workers and international trade tension (and) tariffs remain an impediment to even stronger growth.”

The survey results are compiled into a collection of indexes ranging from zero to 100. Survey organizers say any score above 50 suggests growth. A score below that suggests decline. The survey covers Arkansas, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma and South Dakota.

Economic optimism reflected in the business confidence index fell to its lowest level in three years: 53.7, compared with December’s 54.1.

“However, I expect business confidence to depend heavily on trade talks with China,” Goss said. “Approximately one in five supply manager reported that access to international markets was essential to their firm’s success,” while more than a third indicated that the access was either important or very important, he said.

The regional trade numbers for January were mixed: imports headed higher and new export orders remained weak. The new export orders index inched up to a weak 48.3 from December’s 48.1, and the import index soared to 54.4 from 41.1 in December.

The January employment index jumped to 58.5 from 50.0 in December.

“Overall manufacturing employment growth in the region over the past 12 months has been very healthy at 2.4 percent, compared to a lower 2.3 percent for the U.S,” Goss said.