The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage.By Bill Stone of PNC Wealth Management. NEW YORK ( TheStreet) -- Third-quarter 2011 earnings season for S&P 500 companies gets under way this week. The majority of S&P 500 constituent firms will report third-quarter results over the next few weeks. Consensus estimate S&P 500 earnings per share are $24.68 for the third quarter, representing a 17.1% increase over last year's third-quarter EPS of $21.89. For 2011, the S&P 500 EPS are estimated to be $99.28, which would represent 15.9% growth over 2010's $85.81. Core EPS for the S&P 500, excluding financials, are forecasted to increase 17.3% year over year for the third quarter to $20.76. Core earnings for the S&P 500, excluding financials, for full-year 2011 are estimated to rise 16.2% vs. last year. Energy and materials are estimated to show the strongest rate of profit growth in the third quarter. Energy in particular, is forecasted to show earnings growth of 53.7% for the period vs. third-quarter 2010, aided disproportionately by the large oil firms. Amid much scrutiny financials continue to be the uncertain wild card, with a lack of confidence from the investor community of the sector's growth prospects - banks in particular. Follow TheStreet on Twitter and become a fan on Facebook. Revenues for the S&P 500 are expected to grow 8.9% for the third quarter year over year. In the second quarter, revenues were up a very strong 13.6% vs. the year-earlier quarter.