A new defined benefit pension plan design is on the horizon is that could rekindle employer interest in the plans, benefit experts say.

The design has both defined benefit and defined contribution plan elements.

On the defined benefit side, the plan would provide a minimum pay-related amount contributed by the employer.

Employers would decide the plan’s design in allocating investment income to participants’ account balances. For example, the interest credit could be based on the yield of a target date fund.

On the defined contribution side, the plan would shift investment risk entirely to employees.

If a target date fund did badly, for example, employers would not be liable beyond providing the promised minimum benefit. On the other hand, if a selected investment did well, the employee would receive the entire gain. Regardless, the employee’s account balance never would be less than the amount generated by the plan’s pay-related credits.

Benefit experts say the new design, which would have to be approved by the U.S. Treasury Department, is a middle ground between conventional defined benefit plans in which employers carry all the investment risk and defined contribution plans, such as 401(k) plans, in which employees bear the investment risk.

“We need more options,” said Richard Shea, a partner with law firm Covington & Burling L.L.P. in Washington.

“The beauty of this plan is it would eliminate much of the financial volatility of defined benefit plans, yet provide more retirement income security than defined contribution plans,” Mr. Shea said.

Experts view the risk-sharing design as a positive contrast to defined contribution plans, where employees shoulder the risk, and defined benefit plans, where employees bear the risk.

For example, bearing all of the investment risk is a key reason why employers have moved away from defined benefit plans.

On the other hand, moving to a defined contribution plan-only approach also poses problems.

If employees invest poorly, they may stay on the job longer than either they or their employers want because they will not have earned enough retirement income, leading to productivity issues and blocking the advancement of younger employees.