SAO PAULO, Dec 28 (Reuters) - Engie Brasil EGIE3.SA, the Brazilian subsidiary of France's Engie ENGIE.PA, said on Thursday its board of directors approved the sale of a 15% stake in natural gas pipeline firm TAG to Canadian investment fund Caisse de Depot et Placement du Quebec (CDPQ) for 3.11 billion reais ($641.22 million).

After the conclusion of the deal, Engie Brasil will still hold a 17.5% stake in TAG, remaining in its controlling group with CDPQ and GDF International.

($1 = 4.8501 reais)

(Reporting by Peter Frontini
Editing by Chris Reese)

((Peter.Siqueira@thomsonreuters.com; +55 11 56447727;))