NEW YORK, March 29 (Xinhua) -- U.S. stocks closed mixed Wednesday as investors meditated on the start of the United Kingdom's exit from the European Union.

The Dow Jones Industrial Average fell 42.18 points, or 0.20 percent, to 20,659.32. The S&P 500 increased 2.56 points, or 0.11 percent, to 2,361.13. The Nasdaq Composite Index was up 22.41 points, or 0.38 percent, to 5,897.55.

Britain's ambassador to the EU, Tim Barrow, handed the official letter triggering Article 50 to European Council President Donald Tusk. This commences the country's two-year exit process from the trading bloc.

British Prime Minister Theresa May said on Wednesday that she wanted Britain to emerge as more outward-looking than ever before while addressing the House of Commons to confirm triggering of the Brexit process.

Remarks from several Federal Reserve officials were also in focus. Chicago Fed President Charles Evans said Wednesday that the fundamentals of the economy were increased in 2017, according to the Market Watch.

Boston Fed President Eric Rosengren said the central bank should set a default of rate increase every other meeting this year, while San Francisco Fed President John Williams said he sees three more rate hikes this year.

On the economic front, U.S. pending home sales rebounded sharply in February to their highest level in nearly a year and second-highest level in over a decade, according to the National Association of Realtors Wednesday.

The Pending Home Sales Index jumped 5.5 percent from 106.4 in January to 112.3 in February, beating market consensus.