Forty percent of U.S. workers are planning to delay their retirement due to concerns about out living their savings and fears of rising healthcare costs,according to a survey released on Tuesday by consultants Towers Watson.

Fifty-nine percent of workers who plan to delay their retirement cited the need to keep their healthcare coverage as a reason, while 56% also blamed the decline in the value of their employer-sponsored retirement plan.

The majority of workers who plan to delay retirement expect they will have to work for at least three years more than originally planned.

The survey of more than 9,000 workers conducted in May and June this year found that two-thirds of respondents are paying off their debts -- nearly double the number the company reported in its survey in early 2009.

More than half of respondents have also cut back on their daily spending, the survey found.

"The economic crisis has had a deep effect on employees' attitudes toward retirement and especially on risk ... workers continue to have a fear that they won't be able to afford retirement," said David Speier, a senior retirement consultant at Towers Watson. (Reporting by Helen Kearney, editing by Matthew Lewis)