Stocks limp into holiday; Dow down 15

Mounting speculation that General Motors (GM, news, msgs) will file for bankruptcy protection as early as May 31 sent the automaker's shares tumbling 25% today and helped prevent the Dow Jones Industrial Average ($INDU) from notching a modest gain ahead of the Memorial Day weekend.

The automaker won more cost-cutting concessions today, from its Canadian labor union, as it prepares to enter federal bankruptcy court in a showdown with its bondholders, Reuters reported.

The government is prepared to cancel most or all of its existing debt in the automaker and invest in a "new" GM that could emerge from bankruptcy later this year.

The Dow shed 15 points to close at 8,277. The Nasdaq Composite Index ($COMPX) lost 3 points to 1,692, and the Standard & Poor's 500 Index ($INX) closed down 1 point to 887.

U.S. markets will be closed Monday for Memorial Day.

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Benchmark crude oil for July delivery rose 62 cents today to settle at $61.67 a barrel, lifting energy shares.

Retail gasoline prices continued to climb, with the national average rising 3 cents overnight to $2.39 a gallon, according to AAA's Fuel Gauge report. About 32 million drivers are expected to travel this weekend, according to AAA, up slightly from last year.