Treasury shares

Hi, I was a bit concerned with effect of holding purchased shares in treasury on earnings. Although there will not be any dividend paid on these shares as far as company is concerned(as it look like internal business and the company will "pay itself") but according to registrar record and market quotation the company has these shares included in the number of shares in issue. so at the market level, will we not be computing earning per share based on the initial number of shares? thanks,mike.