Affluent retirees reported much higher levels of concern about the economy in October 2008 than they did in August 2008.

Researchers at MFS Investment Management, Boston, a unit of Sun Life Financial Inc., Toronto, have published figures on that topic in a summary of results from surveys of 500 retirees ages 55 to 75 with at least $500,000 in investable household assets.

All participants retired in 2003 or earlier, and all use a financial advisor.

The percentage who said they were either extremely or very concerned about a major decline in the stock market rose to 65% in October, from 42% in August, and percentage who said they were concerned about investing too aggressively rose to 23%, from 11%.

The percentage who said they wish they had taken fewer risks with investments rose to 17%, from 9%, and the percentage who said they wish they had invested in principal protection or income guarantee products, such as annuities, rose to 12%, from 9%.