(Reuters) - Western Union Co , the world's largest payment transfer company, is in talks to buy a division of Apax Partners LLP's Travelex foreign-exchange business for about $1 billion, Bloomberg reported.

The deal to acquire Travelex's global business-payments unit may be announced as early as next week, the report said, citing people with knowledge of the matter.

Travelex is the world's largest non-bank provider of foreign-exchange services to corporations, according to its website.

Western Union declined to comment.

(Reporting by Brenton Cordeiro; Editing by Prem Udayabhanu)