American Express Business Platinum cardholders will lose a cherished privilege in late March: access to American Airlines Admiral Club and US Airways Club lounges.

Delta Sky Club and Priority Pass Select locations are unaffected.

Notification of the change went out to cardholders via email Dec. 18, but many cardholders were aware of the impending loss of privileges as early as Dec. 4. And they are not happy.

American Airlines and US Airways have been in merger talks since early 2012. The combined airline — the agreement for which was approved last Monday — will carry American Airlines branding with US Air retaining most executive positions.

Cardholders had plenty to say about the loss of access on American Express’s online community. Here’s what these three cardholders had to say yesterday:

“Given that the $200 airline credit and the lounge access is the main reason why I have the platinum, this is a huge blow to the benefit of my Plat[inum card]. Sure, they will offer an extra $200 credit towards American Airlines and US Airways incidentals/travel expenses between March and December of next year, but, nonetheless, since Delta, AA and United own the majority of domestic lounges, taking away yet another third is a huge downgrade. I’m very irritated right now.”

“I got an email about this earlier today, and this was one of the most used benefits of the card for me. I use the Admiral’s Club lounges a good bit and really enjoyed them. I’m going to have to go over all benefits again to decide if I can justify keeping [the card] anymore. I’ve enjoyed having it, and I still have two other AmEx cards, but this really bums me out, honestly.”

“I’ve been Chairman’s Preferred with USAir for several years now, but with the Platinum card never allowing you to go to United clubs, and now they are taking away both AA & USair, I’m downgrading to Gold again and buying the club membership, or fly a little more and get it free.  CLUB ACCESS IS THE ONLY REASON I UPGRADED TO PLATINUM.”

American Express did arrange for cardholders to newly gain access to The Centurion Lounge at both Dallas/Fort Worth and Las Vegas MaCarran International Airports, but it appears the loss of the AA/US Air lounges is a major blow and will cost Amex some cardholders.

Bank Innovation reached out to American Express for comment yesterday with no reply.