HONG KONG (Reuters) -U.S. private equity firm Carlyle Group has agreed to purchase a minority stake in Quest Global Services that values the engineering outsourcing firm at $2 billion, two people with knowledge of the matter told Reuters. Carlyle on Tuesday announced that the firm and Singapore-headquartered Quest Global had entered an agreement on the transaction, which will be funded by equity from Carlyle's funds in Asia and financing from banks, without disclosing any financial details. Quest Global investors Bain Capital and Advent International will exit in the transaction, while ...