Delta SkyMiles credit card holders will soon gain a reprieve from the airline's fee for a first checked bag.

Atlanta-based Delta Air Lines said those who have American Express Delta SkyMiles credit cards will be able to check one  bag for free on every Delta flight starting June 1. The benefit is valid for up to nine people in the same reservation. It applies to those with consumer and small business gold, platinum and reserve Delta SkyMiles credit cards.

For most travelers on domestic flights, Delta's first checked bag fee is $23 if paid when checking in online and $25 if paid at an airport kiosk, ticket counter or curb. Delta said it will waive the first checked bag fee for SkyMiles credit card holders during check in.

The airline already waives first and second checked bag fees for first class and business class passengers, elite SkyMiles Medallion members and those who buy full fare Y class economy tickets.

Delta is offering the benefit as it continues to tries to gain more customers of its merger partner Northwest Airlines as Delta credit card holders. Delta closed its merger with Northwest in 2008. American Express will run advertisements about the new baggage fee benefit in former Northwest hub cities Detroit, Memphis and Minneapolis/St. Paul, which are now Delta hubs.