Lingering concerns about the political future of Greece pushed US and global stock markets lower amid slow trading ahead of the holiday. Greek stocks stabilized on Tuesday following Monday's volatility, after the government was forced to call elections that could create more economic turmoil. 'An election puts all sorts of doubt on the future of the bailout agreement,' said one market strategist. Stocks were expected to be quiet on Wednesday. In other markets, the dollar fell against the euro and yen. Benchmark US crude oil rose 51 cents to $54.12 a barrel in New York. Gold continued its march higher, rising $18.50 to $1,200.40 an ounce. Silver and copper also rose.