The Power Workers Union agreement comes as the Liberal government prepares to sell 60 per cent of the giant utility.
A copy of the agreement obtained by The Canadian Press in May shows existing workers will get shares in the utility equal to 2.7 per cent of their base pay every year from 2017 until 2028.
The government says the share payments are made possible as a result of increased employee pension contributions.
The ratified deal gives members of the Power Workers Union a one-per-cent annual wage increase.
The government says the increase will be offset by contracting out what it calls "non-core" services.
Workers also agreed to hike their pension contributions but Hydro One will make cash and share payments to help existing employees cover the higher payments.
Overall, Energy Minister Bob Chiarelli says the "net-zero collective agreement" won't cost taxpayers any more money.
He says the agreement will have a favourable impact on electricity rates for years to come.