The West German Bundespost is belatedly responding to the growing clamour over its exorbitant telephone rates, saying that it plans to cut telephone rates to the US by 15% and also to cut other domestic and international rates on September 1; international leased line charges are to be cut and restrictions on traffic volume on domestic and international leased lines are to be lifted early next month; the Bundespost also plans to join the UK in using the transatlantic satellite links planned by Pan American Satellite Corp when its bird goes up later this month on Ariane; the Ariane launch had been set for June 10, but has been hit by a computer problem and has been postponed to June 15 at the earliest.