Some airlines will hire you before you have your ATP, as long as you have your Commercial certificate and other specific ratings/certificates. CAVU is correct that you will need quite a few more hours under your belt. My new-hire class average was 4000 hours.
Having said that, there's no reason you shouldn't make some inquiries to the specific companies, or AirInc (like CAVU mentioned). It is never too early to learn what the companies are looking for, so you can prepare yourself for the future. Best wishes!
[ 13 July 2001: Message edited by: McD ]