Chicago-based Ameritech.net has followed AOL and Microsoft’s WebTV Plus in raising its monthly charges for internet access. The company says its subscriber numbers have doubled in the last six months and that customers are spending 30 per cent more time online. It plans to increase network investment by 66 per cent over its 1997 figure in a bid to meet these demands. Ameritech’s fee for unlimited access has been raised from $19.95 to $21.95 per month. The price of a year’s subscription has also risen, from $189 to $213, the equivalent of $17.95 per month. The base rate of $8.95 for ten hours remains unchanged. Recently graded A+ by independent net performance watchdog Inverse Network Technology, Ameritech still offers a cheaper option than WebTV Plus on $25 per month (CI No 3,380) and AOL on $22 (CI No 3,377).