Before the post-election downturn in the stock market, employee 401(k) accounts grew to their highest level in more than a decade.

Average balances swelled to $75,900 for three months that ended in September and average annual employee contributions reached $5,900, up more than 7 percent from the same period five years ago, based on an analysis of more than 12 million accounts administered by Fidelity Investments.

The nation’s largest 401(k) provider said Thursday that average balance at the end of the third quarter was up 4.2 percent from the end of the previous quarter and 18 percent from the year-ago average of $64,3003.

Meanwhile, average annual employer contributions – sometimes called a company match – rose to $3,420 at the end of the third quarter, up 19 percent from the third quarter of 2007 - just before the recession began.