Private equity firms Bain Capital and Boyu Capital are among bidders for SML Group Ltd., a closely held garment label maker for fashion brands and retailers globally, people familiar with the matter said.

MBK Partners has also lodged initial offer for the business, said the people, who asked not to be identified as the information isn’t public. Hong Kong-based SML is working with Citigroup Inc. to seek a buyer for the business, Bloomberg News reported in January. A sale could fetch about $400 million to $500 million, one of the people said.

SML makes woven and printed labels, price tickets, hangtags as well as zippers and buttons, according to its website. Founded in a warehouse office in 1985, the company has since expanded both organically and via acquisitions. It counts offices and production sites in 30 countries including the U.S., Mexico, Spain and Indonesia.

Considerations are still ongoing and the buyout firms could still decide against pursuing the assets, the people said. Representatives for Bain Capital and MBK declined to comment, while representatives for Boyu and SML didn’t immediately respond to requests for comment.