The breakneck growth of U.S. public pension assets paused in the third quarter of the year, due to falling earnings, U.S. Census data released on Wednesday showed.

The $3.31 trillion in cash and security holdings was slightly less than the record $3.37 trillion of the second quarter. That was still above $3.06 trillion in the third quarter of 2013.

Since the third quarter of 2012, public pension assets had steadily increased, setting record highs every three months.

But earnings on the funds' investments, which provide the lion's share of their revenue, fell $43.03 billion in the third quarter. It was the first loss for the investments since the second quarter of 2012, when earnings fell $18.51 billion.

The contraction came from the pensions' largest asset holding, corporate stocks. Pension funds' corporate stocks fell 0.7 percent from the previous quarter to $1.17 trillion. Still, that was 10.3 percent more than the third quarter of 2013.

International securities also fell from the previous quarter, by 4.9 percent to $624.5 billion. They decreased 2.1 percent from the year before, as well.

Treasuries, meanwhile, rose to $308.1 billion, which was up 0.1 percent from the second quarter and 15.8 percent from the third quarter of 2013. Corporate bonds were up 2.7 percent from the previous quarter to $381.3 billion, which was also 18.4 percent higher than the third quarter of 2013.

Both employee contributions, $9.83 billion, and government contributions, $25.04 billion, were higher than in the third quarter of 2013, Census data showed. So were payments. In the third quarter, public pensions paid $62.32 billion to retirees and employees, up from $59.32 billion in the third quarter of 2013.