BEIJING -- Changsheng Bio-technology, a major Chinese vaccine maker, has received notice of a mandatory delisting from the Shenzhen Stock Exchange, the company said in a statement Tuesday.

According to the statement, the Shenzhen bourse has decided to move ahead with mandatory delisting procedures after starting preparations in November over major law violations of Changsheng's major subsidiary Changchun Changsheng Life Sciences Limited.

Changsheng shares will resume trading Wednesday for 30 trading days marked by delisting risk warnings before entering a six-month suspension, which will pave the way for ultimate removal from the Shenzhen exchange.

In October, authorities revoked the pharmaceutical production license and imposed a fine of more than 9.1 billion yuan ($1.32 billion) on Changchun Changsheng Life Sciences Limited for the illegal production of vaccines.