Stocks: All eyes on Greece

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NEW YORK (CNNMoney) -- U.S. stocks were headed for a lower open Monday, after European officials failed to agree on a solution for Greece's debt crisis.

Dow Jones industrial average (INDU), S&P 500 (SPX) and Nasdaq (COMP) futures were about 0.5% lower ahead of the opening bell. Futures measure current index values against perceived future performance.

Greek debt woes have been pressuring stock markets around the world in recent weeks, as investors worry that the country will default on its debt and the crisis will spread to other countries.

European finance ministers said Monday that Greece won't receive fresh loans until mid-July -- news that is likely to only exacerbate those fears.

Europe's sickly banks

"There's a lot that could happen between now and mid-July, and markets aren't going to believe the debt situation is going to be resolved until it's actually resolved," said David Jones, chief market strategist at IG Markets.

Adding fuel to the fire, credit agency Moody's said Friday that it was putting Italy on watch for a possible credit rating downgrade.

Despite Moody's warning, the Dow managed to break its six-week losing streak.

The Bull with the broken halo - StockTwits

But eurozone jitters, coupled with continued worries about an economic slowdown in the U.S., could easily erase those gains, said Jones.

"We've had fairly gloomy economic data over the last few weeks, so there's nothing there to balance out the Greek news," said Jones. "It could be another difficult week ahead for the market."

World markets: European stocks fell in morning trading. Britain's FTSE 100 slumped 0.8%, the DAX in Germany tumbled 1.4% and France's CAC 40 dropped 1.3%.

Asian markets ended the session mixed. The Shanghai Composite lost 0.8%, the Hang Seng in Hong Kong slipped 0.4% and Japan's Nikkei ended just above breakeven.

Companies: Ford Motor Co. (F, Fortune 500) plans to invest $1 billion to revamp its struggling Lincoln brand, the Wall Street Journal reported Sunday citing dealers briefed on the plan. Shares of the automaker fell 1% in premarket trading.

PNC Financial Services Group (PNC, Fortune 500) said early Monday that it will buy the U.S. retail banking division of Royal Bank of Canada (RY) for $3.45 billion.

Shares of Peabody Energy Corp (BTU, Fortune 500) and Consol Energy (CNX, Fortune 500) were gaining traction in early trading. But shares of land driller Nabors Industries (NBR) fell 4% after the company trimmed its second-quarter outlook.

Chinese social networking site Renren (RENN) is slated to report results after the market close. Shares of Renren, which went public last month, slid 1% in premarket trading. The stock has declined 50% from its IPO price.

Currencies and commodities: The dollar gained against the euro, the Japanese yen and the British pound.

Oil for July delivery slipped $1.30, or 1.4%, to $91.71 a barrel, extending steep losses from the previous week.

Gold futures for August delivery fell $2.10 to $1,537 an ounce.

Bonds: The price on the benchmark 10-year U.S. Treasury rose, pushing the yield down to 2.90% from 2.94% late Friday.