NEW YORK — American Express will increase the annual fee on some of its most popular charge cards, the company said Thursday, but the company also increased some of those cards' benefits as well. It's the latest move by American Express to strike a balance between keeping its loyal, mostly affluent customer base, but at the same also raise revenue when the company is losing one of its biggest business deals. American Express Co. said the fee on its Gold Card will go to $160 a year, from the current $125 a year. The Premier Rewards Gold Card will have an annual fee of $195, up from $175. The increases are effective June 1. At the same time, American Express is adding some benefits to those cards. The Premier Rewards Card will now have a $100 credit for incidental airline fees such as baggage and will wave foreign transactions fees while traveling internationally. Those types of benefits were typically reserved for the company's Platinum Card, which carries a much higher annual fee. AmEx has been looking for new sources of revenue since it announced last month it would be ending its exclusive deal with Costco, one of the company's biggest merchants. – AP