Yes they can do; the same we are following for property documents means the first page is stamp paper and the rest of all are bond papers. the company seal and concern authority signature is valid.
9th July 2018 From India, Hyderabad
The normal practice is the first page is on the company's letter head, while the second and successive page(s) (if any) are on the company's blank water mark sheets. The first and successive pages carry the initials of the authorized signatory , while the last page has the signature in full.
Putting the company's rubber stamp is optional.
This is the stated practice here.
Arif ur Rehman
10th July 2018 From Pakistan, Karachi