NEW YORK - US stocks opened mixed on Wednesday as investors adopted a cautious wait-and-see approach as major American corporations began reporting their second quarter earnings amid uncertain economic times.

The blue-chip Dow Jones Industrial Average rose 21.82 points (0.19 per cent) to 11,406.03 during opening market activity.

The technology-dominated Nasdaq composite index lost 7.60 points (0.33 per cent) to 2,286.84 and the Standard & Poor's 500 index gained 2.91 points (0.23 per cent) to 1,276.61.

Stocks got off to a lacklustre start a day after Wall Street rallied in the wake of a sharp fall in oil prices. Oil prices bounced back somewhat on Wednesday amid renewed geopolitical jitters over Iran's nuclear ambitions.

Aluminum giant Alcoa reported an expected dip in profits Tuesday after the market close, and many analysts say the credit crunch will likely have exacted a toll on bank earnings.

'More reports like Alcoa's, which convey the market's view on earnings has gotten too negative, could give way to an earnings season rally if oil prices remain in check and the financial stocks start acting better,' said Mr Patrick O'Hare, a market analyst at Briefing.com.