Delta Air Lines is raising the price of memberships to its airport Sky Clubs, saying the rate increases will enable it to continue to upgrade the clubs.

The clubs, which are located at a number of airports where Delta operates and throughout the concourses at Hartsfield-Jackson, have complimentary food, drinks and a lounge-like atmosphere away from the crowded gate areas. The airline said it had upgraded food, drink and amenities such as power outlets and furniture in the clubs over the past couple of years.

Atlanta-based Delta will charge $495 for an individual Sky Club membership starting in 2017, up from $450 this year.

An executive membership, which allows club members to bring in guests without an extra fee, will cost $745 in 2017. That's up from $695 this year.

But Delta is lowering the rate to buy Sky Club memberships using miles. It will take 47,000 miles to get an individual membership in 2017, down from 70,000 this year. And the rate for an executive membership will be 70,000 miles next year, instead of 110,000 miles this year.

That could incentivize Delta frequent fliers to use more of their miles -- which allows Delta to lower its liability of accumulated miles.

However, many users of Sky Clubs get free memberships as part of their American Express platinum card benefits or as diamond-level elite frequent fliers on Delta.

A day pass to access a Sky Club costs $59. Delta says less than 1 percent pay for a day pass to enter.

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