U.S. companies are expected to report their worst sales decline in nearly six years when they post second-quarter results, giving investors reason to worry about future profits. Companies have managed to drive 2015 earnings by cutting costs, a practice they turned to during the financial crisis. They have also used share buybacks to lift earnings per share. But it is hard to make a case for sustained earnings growth given forecasts for a second-straight quarter of revenue decline at S&P 500 companies, which begin reporting financial results in earnest this week. Though analysts expect corporate America to show a decline in second-quarter profits, according to Thomson Reuters data, some strategists expect them to defy those forecasts and eke out a gain, just […]