This year’s rebound in corporate earnings is losing steam as slower economic growth and greater strain on consumers threaten sales and profit margins at companies from Texas Instruments Inc. to Google Inc., Bloomberg reported.

Earnings per share for the Standard & Poor’s 500, excluding financial companies, rose 14 percent in the third quarter, the smallest gain since the end of 2009, analysts’ estimates compiled by Bloomberg show. That compares with 19 percent in the second quarter and 20 percent in the first. Analysts have begun reducing forecasts for the current quarter and beyond, Bloomberg said.

Chipmaker Texas Instruments and air compressor maker Ingersoll Rand Plc are among companies that have lowered their guidance because of faltering demand. With U.S. unemployment stuck above 9 percent, political squabbling about the government debt ceiling and a downgrade of the nation’s credit rating, confidence has been sapped, said Matt McCormick, of Bahl & Gaynor Inc.

“What started in August as a crisis of confidence hasn’t been resolved,” McCormick said. “This is a grind-it-out economy. We’re in a situation where it’s still going to take several years to rebuild our economic house.”

S&P 500 earnings, excluding financials, are forecast to slow to 12 percent growth in the fourth quarter and 9 percent in the first quarter of 2012.

The U.S. economy will expand 1.6 percent this year after growing 3 percent in 2010, according to the average of 66 economist forecasts. Consumer spending slowed in August to 0.2 percent as incomes dropped for the first time since October 2009, and the Bloomberg Consumer Comfort Index showed the worst quarterly performance in more than two years.