AT&T, the nation's largest wireless carrier, has announced it will reduce the $175 termination fee it charges customers who end their wireless contracts early.

Starting May 25, new and renewing customers will pay $5 less for every month they fulfill of their one- and two-year contracts. For example, if you've got one year left in a two-year contract, canceling will cost you $115. However, if you renew your contract or start a new one with AT&T before May 25, expect to pay the flat early termination fee of $175. (Better to wait if you can).

AT&T joins Verizon Wireless, which began pro-rating early termination fees in 2006. Like AT&T, Sprint and T-Mobile also announced in late 2007 that they would take similar action. Sprint and T-Mobile both charge $200 if you end your contract before it is up.

Two weeks ago, U.S. Sen. Amy Klobuchar, D-Minn., sent letters to executives at AT&T, Sprint and T-Mobile urging them to provide assurances that they plan to follow through with those promises. Klobuchar introduced legislation last year requiring wireless carriers to prorate these early termination fees.