U.S. stocks closed higher on Wednesday as investors digested a slew of major economic data.

The Dow Jones Industrial Average increased 306.33 points, or 1.26 percent, to 24,667.78. The S&P 500 increased 34.15 points, or 1.27 percent, to 2,724.01. The Nasdaq Composite Index rose 65.86 points, or 0.89 percent, to 7,462.45.

The U.S. private sector added 178,000 jobs in May, missing the market consensus of 190,000, according to the National Employment Report released by the ADP Research Institute on Wednesday.

The ADP figure is widely seen as a pre-indicator for the non-farm payrolls report due on Friday.

Meanwhile, U.S. real gross domestic product (GDP) increased at an annual rate of 2.2 percent in the first quarter of 2018, according to the second estimate released by the Commerce Department on Wednesday. The economy grew 2.9 percent in the fourth quarter last year.

Investors continued to be concerned about Italian politics.

With an assertive move to put a temporary end to an 85-day-long stalemate, Italian President Sergio Mattarella on Monday named economist Carlo Cottarelli as Italy's new prime minister-designate.

Cottarelli was asked to form a technical cabinet able to lead the country to snap elections -- either in late 2018 or early 2019 -- after the efforts by anti-establishment Five Star Movement (M5S) and rightwing League to form a government failed on Sunday.

All three major indices closed lower on Tuesday amid uncertainties about Italy's political situation, with the Dow plunging 500 points at session low.