It's time to break up with American Express

Get ready to get rid of your American Express card.

News broke Thursday that the credit card company has lost an antitrust lawsuit over whether it could stop merchants from asking customers to use other credit cards.

Other credit card companies, particularly Visa and Mastercard, typically charge merchants that accept their credit cards lower fees than AmEx does.

The higher fees that AmEx charges merchants mean that they can offer better rewards to the customers who use their cards.

And so for cardholders, Thursday's ruling means that their rewards are likely to get worse over time.

In addition to losing the antitrust lawsuit, AmEx also just lost two lucrative partnerships: the first with Costco, and the second with JetBlue. It also announced 4,000 job cuts back in January.

None of these things would necessarily force the company to cut its high merchant fees. However, this lawsuit means that restaurants and shops are free to ask customers to use other credit cards (this is in addition to the many that already refuse to accept AmEx).

That's going to put pressure on AmEx to lower their fees in order to be more competitive with Visa and Mastercard if they don't want to lose more market share.

Lower fees mean fewer rewards for consumers, and for American Express card members, potentially higher annual fees.

So if rewards got you sign up for an AmEx, you might as well apply for that Visa card today.