ATLANTA — Delta Air Lines Inc. is taking a page from the cell-phone industry and will be allowing elite frequent fliers to roll over miles earned above their qualification status in a given year so they have an easier time maintaining that status or improving to a higher one the next year.

ATLANTA — Delta Air Lines Inc. is taking a page from the cell-phone industry and will be allowing elite frequent fliers to roll over miles earned above their qualification status in a given year so they have an easier time maintaining that status or improving to a higher one the next year.

The world's biggest airline operator planned to announce today enhancements to its SkyMiles Medallion program that will go into effect over the next nine months.

Atlanta-based Delta has three elite frequent-flier statuses — silver, gold and platinum — and will be adding a fourth, diamond. Customers reach those levels by flying a lot — you reach the lowest level after flying 30 segments in a year — and in return they get extra benefits like priority boarding, waived checked bag fees and free upgrades.

Now, Delta says it will allow customers to retain any Medallion qualification miles earned above a Medallion threshold at the end of the year, supplementing the ability to earn status the following year.