The average 401(k) account balance rose 10 percent in 2004, reaching a five-year high of $61,000, according to preliminary study data provided by Fidelity Investments.

“It’s a combination of market action and net contributions,” said Steve Deschenes, executive vice president of institutional retirement services with Fidelity, a Boston-based investment firm.

Still, the average 401(k) balance remains below 1999 levels of $64,000. In 2000, when the stock market bubble burst, the average 401(k) balance fell to $55,000 and continued to spiral downward until it hit $44,000 in 2002.

The average balance began to tick higher again in 2003 when it again hit $55,000, according to Fidelity data.

Workers appear to be contributing roughly the same percentage of their salary to their 401(k) plans as they have in years past, indicating that stock market moves are primarily responsible for the recent declines.