Fewer than two in 10 Americans are confident of their ability to invest in the stock market, although 60 percent still believe equities are important in a portfolio.

The findings come in preliminary results of a survey by AXA Equitable Life Insurance Company that polled 1,000 American between the ages of 25 and 70.

In 2008 the financial crisis wiped more than 37 percent off the value of share prices as measured by the broadS&P 500 index. That has left many investors shell shocked and distrustful of equities.

U.S. investors pulled around $242.7 billion out of stock funds in 2008 and 2009 and put $401.7 billion into safer bond funds over the same period, according to the Investment Company Institute.

That seeming aversion to the stock market came even as the S&P 500 jumped 65 percent from March 2009 to the end of the year.

In the first decade of the new century the value of top 500 U.S. stocks, which make up a large part of retirement assets, have fallen more than 24 percent.

Because of that and an increase in life expectancy, the survey showed 42 percent of Americans will delay retirement by an average of six years. More than four in 10 now expect to retire at 68 rather than 62.

Falling stock prices have eaten into family nest eggs. Almost three in 10 Americans plan to go back to work after retiring, according to the survey, which shows 84 percent are worried about inflation and losing money.

The survey was conducted in December 2009. Respondents includes financial decision makers with household income of at least $75,000 or investable assets between $250,000 and $999,999. There is a margin for error of plus or minus 3 percent.

Full results of the survey entitled A Survey of Concerns and Expectation will be released next week.