Earnings pessimism among U.S. chief executive officers is climbing to levels last seen when the Standard & Poor's 500 Index was mired in bear markets.

Over the last four weeks, the ratio of companies saying profits will trail estimates compared with those saying they will exceed them climbed to 4.3, according to 69 earnings previews compiled by Bloomberg. The rate matches peaks reached in February 2009 and October 2001, the data show.

Warnings that estimates are too high by companies from Intel Corp. to Caterpillar Inc. came even after analysts lowered predictions for third-quarter income growth by 11 percentage points this year. Bears say the 1.7 percent decrease in profits predicted by analysts, the first quarterly retreat in three years, will limit gains in equities. Bulls say stocks can keep rallying as companies have an easier time beating forecasts.