Wall Street set to open higher on Greek hopes

Wall Street was set to open higher on Monday on optimism that Greece may be able to strike a last-minute deal with its international creditors to avert a default.

EU Economic Commissioner Pierre Moscovici said he was "convinced" that euro zone leaders holding an emergency meeting in Brussels would find a way out of the Greek crisis.

Global stocks were higher on Monday with European shares hitting their highest level in over a week on the hope of a solution to Greece's debt crisis.

"The Greece situation has a psychological effect on investors," said Peter Cardillo, chief market economist at Rockwell Global Capital in New York.

"If Greece were to exit the euro, it raised speculation on the future of its peripheral nations and so if we do see a breakthrough in the talk, expect the markets to rally."

U.S. stocks closed lower on Friday as Greek worries weighed but the three major indexes were higher for the week on hopes that the U.S. Federal Reserve's planned rate hike will be slower than previously anticipated.

Sales of previously owned homes likely recovered last month, data from the National Association of Realtors is

expected to show. Economists expect existing home sales to have jumped 4.4 percent to a 5.26 million unit-rate in May. The data is expected at 10:30 a.m. ET (1430 GMT).

S&P 500 e-minis were up 13.5 points, or 0.64 percent, with 187,043 contracts traded at 8:43 a.m. ET. Nasdaq 100 e-minis were up 32 points, or 0.71 percent, on volume of 24,662 contracts while Dow e-minis were up 109 points, or 0.61 percent, with 21,594 contracts changing hands.

The futures were also boosted by M&A chatter over the weekend as companies rush to make the best of the zero-rate interest environment before an expected hike this year.

Cigna's shares rose 8.8 percent to $168.90 in premarket trading after the health insurer rebuffed Anthem's $47 billion merger proposal on Sunday. Anthem was up 2.4 percent to $169.

Humana was up 2.2 percent at $206.70 as sources said Cigna along with Aetna are participating in an auction to acquire the company. Aetna was up 3.6 percent at $128.50.

Williams Cos jumped 27.4 percent to $61.60 after Energy Transfer Equity confirmed it had made a $48 billion unsolicited bid for the natural gas pipeline company. Williams rejected the offer as too low.

Fitbit rose 7.5 percent to $34.95, building on last week's impressive IPO, which valued the maker of wearable fitness-tracking devices at $6.5 billion.