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 ofconfidence 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.
Consensus third-quarter revenue projections are for 12.9% growth year-on-year, excluding financials and utilities -- the seventh consecutive double-digit increase since fourth-quarter 2009. Top-line growth and better pricing are anticipated to have a positive impact on results. The strongest revenue trends are expected from energy, owing to higher oil prices, followed by materials and technology. Health care and consumer discretionary are estimated to post the lowest revenue gains outside of financials. Margins are expected to contract to around 8.51% in the third quarter, excluding financials and utilities, compared with the 8.95% realized in the second quarter. Historical trends indicate margins seasonally dip in the third quarter. Margins have likely crested, having expanded from trough levels in first-quarter 2009 at 5.77% to the 8.95% achieved in the second quarter of this year. Upside surprises on the revenue front could boost margins. We may begin to see firms passing on costs to customers, attempting to control margin contraction. Typically, profit forecasts for the following year become a topic of focus during third-quarter conference calls. As we have noted in the past few quarters, company leaders have voiced concerns about broader global and economic uncertainties. This negative tone has become more prevalent in recent weeks as corporate leaders have voiced caution about the outlook for their businesses and the impact global events have had on their customers. Given the emotional state of the markets, commentary from leaders is likely to be more closely monitored this quarter, particularly as analysts frame up their models for a closer look at 2012. Given the relative strength of earnings, solid margin levels, and double-digit top-line growth, partially offset by tougher comparisons, we believe the S&P 500 is on target for delivering at or near-record profits for the third quarter. Expectations for 2012, and continued uncertainty regarding global events could override positive market reactions to the strong corporate results.