NEW DELHI: Markets regulator Sebi has come out with new norms, that entails filing of fresh offer documents in those cases where there has been a change in issue size. Under the new rules, filing of a fresh offer document is required in case of any increase or decrease in the estimated issue (new) size by more than 20 per cent, Sebi said in a notification dated December 31.At present, such requirement is both for fresh issues and offer for sale (OFS).In case of an OFS, where there is a change in the number of shares offered for sale, or in the estimated issue size, by more than 50 per cent, the capital markets watchdog said that fresh offer document will be needed.In case an issue made other than through the book building process, Sebi said minimum 50 per cent will be allocated to retail investors and remaining to individual applicants other than retail investors as well as other investors including corporate bodies or institutions, irrespective of the number of specified securities applied for.To give effect to these norms, Securities and Exchange Board of India (Sebi) has amended its capital and disclosure requirements regulations.