Stock index futures fell on Friday after General Electric Co's quarterly earnings sank and Google Inc, despite beating profit expectations, pointed to weaker advertising and revenue growth.

Bank of America Corp shares slipped after it posted a lower quarterly profit, hurt by a surge in troubled loans as more credit card and mortgage customers fell behind on payments.

Google shares fell more than 3 percent before the opening bell after the Internet search company's results late Thursday beat Wall Street expectations, but the weak economy and a slump in advertising spending took a toll on revenue growth and the price of search ads.

Wall Street capped four days of gains on Thursday, and IBM Corp added to the positive sentiment after the closing bell as the company sharply raised its full-year earnings forecast. Its shares rose more than 1 percent before the bell on Friday.

Also after the U.S. market's close on Thursday, CIT Group said its board of directors and management were evaluating ways to improve liquidity and that the lender was in discussions to secure financing.

S&P 500 futures were 4.4 points lower and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures fell 6 points, and Nasdaq 100 futures fell 1.75 points.

Economic data on tap includes housing starts and building permits for June at 8:30 a.m. EDT.

(Reporting by Rodrigo Campos; Editing by Padraic Cassidy)