LIMA, March 21 (Reuters) - Niagara Energy is launching a bid to buy up to the entirety of shares in Enel Generacion Peru, a South American power generation subsidiary of Italian utility Enel, the Lima stock exchange said in a statement on Thursday.

The offer is valid for 20 days and is offering around $0.47 per share, the exchange said. (Reporting by Marco Aquino; Editing by Valentine Hilaire)