AIG SunAmerica Retirement Markets Inc. has introduced the MarketLock For Life Plus guaranteed minimum withdrawal benefit.

AIG SunAmerica, Los Angeles, a unit of American International Group Inc., New York, is making the option available with the company’s Polaris and Seasons variable annuities.

The new rider gives individuals and married couples the ability to lock in minimum withdrawals based on a benefit base.

If purchasers wait to start taking withdrawals, the base used to compute withdrawals will increase at least 6% per year for the first 10 contract years.

If investment returns on contract assets are strong, the increases in the benefit base could be higher, AIG SunAmerica says.

In many cases, purchasers can extend the “step-up” period for additional 5-year periods, AIG SunAmerica says.

The rider is available at contract issue for an additional annual fee of 0.65% for the single life option; 0.90% for the joint life option.

The fee is a percentage of the benefit base.

AIG SunAmerica is issuing the rider and the underlying annuities through AIG SunAmerica Life Assurance Company and First SunAmerica Life Insurance Company., and those companies are responsible for backing the rider guarantees.