The government's chief economic forecasting gauge plunged 0.7 percent in March, the second straight decline and the biggest drop in eight months, the Commerce Department said Friday. It was the first time the Index of Leading Economic Indicators, which dropped 0.3 percent in February, had posted back-to-back declines since it fell for five straight months from September 1987 through January 1988, the months surrounding the October stock market crash. Analysts said the latest negative signals are in line with signs that the U.S. economy is losing steam and with expectations that the slowdown will become more pronounced as the year progresses. March's decline in the index, which is designed to predict economic activity six to nine months into the future, was the biggest falloff since a 0.8 percent drop last July.