The percentage of 401(k) plan sponsors who say participation by eligible employees is greater than 70 percent rose from 63 percent last year to 67 percent this year, according to a survey by Deloitte Consulting LLP.

Similarly, the percentage of plans with participation rates exceeding 90 percent increased from 19 percent to 24 percent over the same period.

The survey, which included 830 plan sponsors, also uncovered increases in time-based lifestyle funds, auto-enrollment, and step-up programs.

A time-based lifestyle fund is one that targets plan participants according to their expected retirement date and gradually shifts the fund's asset allocation from stocks to bonds as the target retirement date approaches.  Approximately 44 percent of respondents reported offering this type of investment option now, up from 28 percent last year. 

Overall, respondents provided 17 investment choices to the average participant versus 15 in the last survey. 

Forty-nine percent of surveyed plan sponsors allow employees to participate in 401(k) plans immediately upon being hired, up from 45 percent in last year's survey. 

Twenty-three percent of respondents reported automatically enrolling new employees, up from14 percent a year earlier.