US stock indexes open higher, a day after a plunge, as investors speculate on late Greek deal

U.S. stocks moved higher in early trading on speculation that the Greek government is considering a last-minute attempt to break the deadlock between the country and its creditors.

The Standard & Poor's 500 index rose nine points, or 0.4 percent, to 2,066, as of 10:10 a.m. Eastern. The Dow Jones industrial average climbed 63 points, or 0.4 percent, to 17,660. The Nasdaq composite gained 27 points, or 0.6 percent, 4,985.

Stocks were trimming their losses from Monday, when the market had its worst day of the year after talks between Greece and its creditors broke down, pushing the Mediterranean nation closer to defaulting on its debt. Investors are concerned that Greece's problems could spread through the global financial system.

On Tuesday, there was some optimism that a deal could still be done after Jean-Claude Juncker, the head of the European Union's Executive Commission, made a last-ditch effort to help Greece get a bailout deal.

Greece government says the country will not make its payment due Tuesday to the International Monetary Fund and European Union officials say Greece would lose access to more than 16 billion euros ($18 billion) in financial support once its bailout program expires at midnight.

"Deep down there is a sense that some sort of compromise will be reached before the deadline — it's the eurozone way," said David Madden, market analyst at IG.

Greece will likely remain the focus of attention in markets this week, especially if no deal is reached.

The Greek government called a referendum for Sunday asking Greeks to vote on whether the nation should accept the deal offered by its creditors. If Greeks vote against the proposal, the country could slide into bankruptcy and be forced to leave Europe's common currency.

The Stoxx 50 index of leading European shares was down 0.4 percent, having earlier traded more than 1 percent lower. Germany's DAX was flat, while the CAC-40 in France fell 0.1 percent.

In currency trading, the euro was down 0.3 percent at $1.1186 while the dollar fell 0.3 percent to 122.24 yen.

In energy markets, benchmark U.S. crude was up 47 cents at $58.80 a barrel on the New York Mercantile Exchange. Brent crude, a benchmark for international oils, gained 95 cents to $62.96 a barrel in London.