What is the fine-grained topic of the following text: Baosteel, China's biggest-listed steelmaker, will sell its 54 percent stake in Ningbo Baoxin Stainless Steel, 40 percent stake in Shanghal STAL Precision Stainless Steel and its 20 percent stake in Rihong Stainless Steel to parent Baosteel Group, it said in a statement. Only return the topic.
Baosteel's sale of stakes in various steel companies to parent Baosteel Group