US STOCKS-Wall Street dips on GM loss, oil, jobs data

* Oil rises on tension about Iran's nuclear work

* Hefty loss at GM adds to U.S. auto sector woes

* Biogen sinks biotechs, pulls down Nasdaq

* Dow down 0.5 percent; Nasdaq, S&P off about 0.6 pct (Updates to close, changes byline)

By Steven C. Johnson

NEW YORK, Aug 1 (Reuters) - U.S. stocks fell on Friday as a $15.5 billion quarterly loss from General Motors (GM.N: Quote, Profile, Research) and a rise in oil prices added to fears the economy could slip into recession and concerns about corporate earnings.

A government report showing U.S. employers cut jobs for the seventh straight month in July added to market worries, though the decline in payrolls was not as severe as had been feared. The report also showed the jobless rate jumped to its highest level in four years. For more see [ID:nN01429062].

General Motors' (GM.N: Quote, Profile, Research) second-quarter loss was the latest example of how rising oil prices are hurting consumer spending. Its shares slumped 7.6 percent to $10.23 and weighed on the Dow and S&P.[ID:nN01288721].

Sliding global metal prices and weak manufacturing data around the world knocked the shares of aluminum maker Alcoa (AA.N: Quote, Profile, Research) nearly 5 percent lower. Shares of Caterpillar (CAT.N: Quote, Profile, Research), the mining and heavy equipment maker, fell 2 percent. The two were the top drags on the Dow.