Business sentiment among large manufacturers worsened for the third straight quarter amid concerns over increased trade friction and the impact of natural disasters, according to the Bank of Japan’s tankan survey.

The key index measuring confidence among companies such as automobile and electronics makers, released Monday, stood at plus 19 in the September survey, down two points from June. The result was weaker than the average market forecast of plus 22 in a Kyodo News poll.

This is the longest streak of negative results for the tankan since a six-quarter run between December 2007 and March 2009, lending weight to the view that growth in the world’s third-largest economy may have slowed in the third quarter.

By industry, companies selling production machinery were less optimistic as demand from the tech industry slowed, while some firms also voiced worry that U.S. President Donald Trump’s efforts to cut his country’s trade deficit with China, the European Union and Japan.

Trump has threatened to impose steep tariffs on automobiles, one of Japan’s primary exports, though he promised last week to shelve those plans while the two countries negotiate a bilateral trade deal.

Sentiment worsened in the oil and coal industry amid rising crude oil prices, while steel manufacturers were also hit by higher costs for raw materials.

Large manufacturers said they now expect an exchange rate of ¥107.40 against the dollar for fiscal 2018, slightly weaker than the ¥107.26 assumed in the June survey. In general, that would be cause to celebrate for export-reliant manufacturers, but it also means higher import costs.

Meanwhile, sentiment among large nonmanufacturers soured for the first time in two years, with the index for industries including retail and real estate coming to plus 22, down two points. Largely to blame were a string of natural disasters this summer, including massive flooding caused by torrential rain in western Japan in July and Typhoon Jebi in early September.

The latter caused a shutdown of Kansai International Airport — Osaka’s main airport — with hotels and restaurants in the BOJ survey citing a lull in inbound tourists. Transport firms also blamed a stop in distribution channels on the disasters.

“Exports and production seem to have hit their peak . . . and the natural disasters may have hurt consumption,” said Takeshi Minami, chief economist at the Norinchukin Research Institute. “Business confidence may have already peaked out and it looks like Japan is about to hit its economic ceiling.”

Large manufacturers and nonmanufacturers, classified as those with capital stock of more than ¥1 billion, said they plan to increase capital spending by 13.4 percent during the year through next March compared with the previous fiscal year, a 0.3 percentage point downgrade from June.

They said they continued to suffer from a severe shortage of workers, with the index of employment conditions falling to minus 23, the lowest since February 1992.

The tankan covered 9,901 companies between Aug. 27 and last Friday, of which 99.6 percent responded.