Hydro-Québec profits dipped 4.7 per cent to $1.34-billion in the first quarter due to a requirement to purchase electricity from Rio Tinto Alcan during its lockout in Alma, Que., and to lower export revenues and mild winter temperatures.

The public utility earned $1.4-billion in its seasonally strongest period a year ago.

Hydro-Québec purchased $33-million of excess power produced by Rio Tinto Alcan, which is operating at about one-third of capacity at its Alma location after locking out 780 employees on Dec. 30.

Story continues below advertisement

It was also affected by a $30-million decrease in revenue from net electricity exports and a $10-million payment of a required annual contribution to province's Northern Plan Fund.

Revenues for the period ended March 31 were $3.79-billion, compared with $3.82-billion a year ago.

Revenue from electricity sales in Quebec decreased by $116-million to $3.24-billion because of mild winter temperatures, partially offset by sales on Feb. 29 since 2012 is a leap year.

Other revenues were $177-million, an increase of $131-million because extra payments from customers related to climate conditions.