The private company, which operates six nuclear reactors at its site in Kincardine, is withdrawing its site licence applications for the new reactors.
The company told the Canadian Nuclear Safety Commission it will also suspend environmental assessments in both locations.
Energy Minister George Smitherman had publicly opposed Bruce's plans to build new nuclear reactors, and accused the company of trying to influence government policy.
Smitherman said last year that Bruce had "no government support in any form"' for its bid to construct new reactors at Nanticoke.
The Ontario government announced last month that it was delaying its own plan to build two new reactors at Darlington after cost estimates soared billions of dollars beyond expectations.