U.S. stocks declined Thursday as investors meditated on a slew of economic reports.

The Dow Jones Industrial Average fell 158.13 points, or 0.74 percent, to 21,320.04. The S&P 500 lost 22.79 points, or 0.94 percent, to 2,409.75. The Nasdaq Composite Index dropped 61.39 points, or 1.00 percent, to 6,089.46.

U.S. private sector employment increased by 158,000 jobs from May to June, well below market consensus of 180,000, said the June ADP National Employment Report on Thursday.

The ADP report is often seen as a preview for the closely-watched U.S. nonfarm payrolls data due out on Friday.

"Weaker-than-expected ADP (report) increases the odds of weaker-than-expected payrolls, but there is no guarantee. This logic failed as recently as last month, after all," said Chris Low, chief economist at FTN Financial, in a note.

In the week ending July 1, the advance figure for seasonally adjusted initial claims increased by 4,000 from the previous week's unrevised level to 248,000, exceeding market estimates, the U.S. Labor Department reported Thursday.

The non-manufacturing index came in at 57.4 percent in June, which is 0.5 percentage point higher than the May reading of 56.9 percent, the Institute for Supply Management said Thursday.

Meanwhile, U.S. Commerce Department announced Thursday that the goods and services deficit was 46.5 billion U.S. dollars in May, down 1.1 billion dollars from April's revised reading.

Despite mixed economic reports, some analysts attributed Thursday's equity drop to a renewed decline in tech shares amid valuation concerns.