U.S. stocks open sharply lower on Greece fears

U.S. stocks opened sharply lower on Monday, as the intensification of Greek debt crisis rattled market sentiment.

Greece's European partners shut the door on extending a credit lifeline after Greece's surprise move to hold a referendum on bailout terms. Fear of an imminent default by Greece hit Greek banks, a major buyer of Greek government bills, triggering bank runs at weekend and forcing Prime Minister Alexis Tsipras to announce a bank holiday on Monday and capital controls.

The European Union had given formal approval to Greece's imposition of capital controls in it's troubled country on Monday, after an immediate, preliminary assessment by the European Commission, saying Greece's decision was justified.

After the collapse of five month reform-for-cash negotiations with international lenders, the Greek government called on voters to accept or reject the draft deal tabled by lenders on June 25.

The move triggered a series of reactions starting with the Eurogroup rejecting Greece's request for a loan extension to hold a referendum.

Without an agreement on June 30, Greece was unlikely to make the delayed loan installment to the International Monetary Fund causing Greeks to withdraw money from banks.

In the United State, later in the morning pending home sales for May is due. Investors will also keep a close eye on Thursday's nonfarm payrolls report for further indications on the timing of a rate hike.

Shortly after the opening bell, the Dow Jones Industrial Average fell 120.21 points, or 0.67 percent, to 17,826.47. The S&P 500 lost 15.85 points, or 0.75 percent, to 2,085.64. The Nasdaq Composite Index tumbled 59.74 points, or 1.18 percent, to 5,020.77. Endi