Stocks set for a flat open as Street awaits Alcoa to kick off earnings season

U.S. stocks were set for a mixed to flat open Wednesday morning as investors await results from Alcoa (AA) this afternoon. As Alcoa kicks off a second quarter earnings season, many are concerned the company will paint a grim picture for the economy and corporate profits.

Also making the headlines this morning is Google's (GOOG) announcement of a challenge to Microsoft's (MSFT) operating system as well as NRG Energy (NRG) rejection of Exelon's revised hostile takeover bid of $8 billion in stock because it is undervalued.

More here: Before the bell: Futures flat ahead of Alcoa earnings, G-8 summit