U.S. public pension-fund assets dropped during the third quarter for the first time in more than a year as stocks fell amid concern that Europe’s sovereign-debt crisis may curb economic growth, the Census Bureau said.

Assets of the 100 largest public-worker pension plans decreased by $237 billion, or 8.5 percent, to $2.53 trillion by the end of September, the bureau said today in a report. It marks the first decline since the second quarter of 2010.