SBC Communications will offer cable customers <A HREF="http://news.zdnet.com/2100-9595_22-5767816.html?tag=zdnn.alert">three months of free high-speed Internet</A> and satellite television if they switch to SBC's services, the company said Wednesday. The promotion, which SBC says could be worth up to $340 per customer, is the most aggressive attempt to date by a large local telephone company to lure customers away from cable. SBC's move comes a few weeks after it lowered the price of its high-speed Internet service to $14.95 per month for new subscribers in its 13-state region.