ZURICH/FRANKFURT, Nov 11 (Reuters) - Family-owned contract manufacturer PolyPeptide is advancing preparations for a 2021 Zurich stock market listing or potential sale, two people close to the matter said.

The maker of therapeutic peptides, which are used by pharma companies as well as biotechnology groups, is expected to work with UBS and Bank of America on the deal that could value it at about 1.5 billion Francs ($1.64 billion), they added.

Information packages on the company are expected to be sent out to prospective buyers before Christmas, one of the people said.

PolyPeptide was not available for comment, while the banks declined to comment.

PolyPeptide is headquartered in Sweden, but is expected to choose Zurich as a venue for a potential IPO as rivals Lonza and Bachem are listed there.

PolyPeptide Group was founded in 1996 and has since expanded through a series of acquisitions, including buying Lonza's peptides business in 2017.

Peptides are tiny proteins that are used among others in cancer drugs, antibiotics, vaccines or anti-wrinkle agents. ($1 = 0.9148 Swiss francs) (Editing by Jane Merriman)