Major US stock indices fell significantly, as another disappointing report on the US reinforced concerns about the slowdown in the world's largest economy.

Report prepared by Automatic Data Processing Inc. (ADP) and Moody's research agency revealed that US private employers added 135,000 jobs in September, while economists had expected an increase of 140,000. In addition, the August increase was sharply revised to 157,000 from the 195,000 initially reported . Mark Zandi, chief economist at Moody's Analytics, noted that companies have become more cautious in hiring, especially small businesses, and if the business recedes further, unemployment will begin to rise.

The report was released the day after the publication of ISM data, indicating a decrease in activity in the US manufacturing sector to the lowest level in more than a decade. This worried investors, whose confidence in the strength of the US economy was one of the factors supporting the stock market this year.

The Department of Labor plans to release a more detailed monthly employment report on Friday, which includes both the public and private sectors. Non-farm employment is expected to increase by 145,000 jobs in September, after rising 130,000 jobs in August, while unemployment is expected to remain at 3.7%.

Almost all DOW components recorded a decrease (29 out of 30). Outsiders were shares of Walgreens Boots Alliance, Inc. (WBA; -3.46%). Only Johnson & Johnson shares (JNJ; + 1.42%) went up.

All S&P sectors completed trading in the red. The largest decline was shown in the base materials sector (-2.2%).

At the time of closing:

Dow 26,078.62 -494.42 -1.86%

S&P 500 2,887.61 -52.64  -1.79%

Nasdaq 100 7,785.25 -123.44 -1.56%