By Peter Frontini SAO PAULO (Reuters) -Engie Brasil said on Thursday it had reached a deal to sell a 15% stake in natural gas pipeline firm TAG to Canadian investment fund Caisse de Depot et Placement du Quebec (CDPQ) for 3.1 billion reais ($641 million). CDPQ, Canada’s No.2 pension fund manager with C$424 billion ($320.60 billion) under management, will raise its stake in TAG to 50%, while Engie Brasil will own 17.5% and its French parent company will hold the rest, giving it an indirect 50% stake. In 2019, Engie and CDPQ jointly acquired a 90% stake in TAG from state-run oil firm Petrobras f…