Two new surveys indicate American workers are feeling less secure about the course of their retirements.

A national survey sponsored by Putnam Investments found that 52% of respondents said they need a clearer picture of the income they will need to maintain the lifestyle they expect in retirement.

In a separate survey, Prudential Financial found that Americans were losing faith in the nation's employee-sponsored retirement system. The survey found that 84% of Americans would eagerly embrace a fresh approach to the structure of their workplace retirement plans-especially plans with "autopilot" features.

"Our survey found that the losses sustained by American workers during the past two years really drove home the inherent limitations of longstanding retirement plan design," said Christine Marcks, president of Prudential Retirement.

In Putnam's poll of 1,496 Americans, 54% of respondents said they did not have a plan that identified their retirement income needs nor the income their savings could be expected to produce.

Of those enrolled in defined contribution plans such as 401(k) plans, 47% said they were unsure about what type of investments are best to generate income in retirement.

"The natural fears and concerns that permeate the thinking of most investors saving for retirement are further pronounced given the extreme market chaos witnessed in 2008," said Jeffrey Carney, head of Putnam Investments global marketing.