OTTAWA, July 7 (Reuters) - Ontario plans to build three new small modular reactors (SMRs) to help meet rising electricity demand, the provincial government said on Friday, increasing its bet on the new nuclear technology Canada is counting on to help reduce emissions.

The Ontario government is working with utility Ontario Power Generation (OPG) to start planning and licensing the reactors at the Darlington nuclear site, where Canada's first grid-scale SMR is already under construction.

"A fleet of SMRs at the Darlington New Nuclear Site is key to meeting growing electricity demands and net zero goals," OPG CEO Ken Hartwick said in a statement.

Nuclear reactor construction requires provincial and federal regulatory approvals, and the three additional SMRs could come online between 2034 and 2036, according to the statement. Ontario is Canada's most populous province and home to finance capital Toronto.

The expansion "will ensure we have the reliable, affordable and clean electricity we need to power the next major international investment, the new homes we are building and industries," Ontario's Energy Minister Todd Smith said in the statement.

An energy crisis triggered by the Ukraine war as well as a global push toward lowering emissions has renewed interest in nuclear power. Next-generation SMRs are seen as an efficient, quickly-built way to accelerate the shift away from fossil fuels as G7 nations target net-zero emissions by 2050.

Canada has already backed SMR technology with a C$970 million ($730.04 million) financing pledge for OPG's first reactor at Darlington.

Nuclear power currently provides about 50% of Ontario's electricity supply and the four SMR units are expected to produce a total 1,200 megawatts (MW) of electricity, enough to power 1.2 million homes.

OPG's first SMR unit, being constructed in partnership with GE Hitachi Nuclear Energy, SNC-Lavalin, and Aecon, is expected to be completed by 2028. ($1 = 1.3287 Canadian dollars) (Reporting by Ismail Shakil in Ottawa; Editing by David Gregorio)