The agreement announced last week with a syndicate of underwriters, led by Canaccord Genuity Corp, was originally designed to raise $68 million (US$52 million) for exploration expenses.

It would offer 14 million flow-through shares at C$2.85 to Quebec residents in the first tranche, and 12.1 million flow-through shares at $2.30 to residents outside Quebec in the second tranche.

A day later, Osisko said the offer was amended to include a further 2.6 million common shares at $1.70 to raise a further $4.5 million (US$3.4 million).

It said the underwriters also had the option to increase the offering of common shares by almost 1.2 million which could lift proceeds by $2 million (US$1.5 million).

Osisko said the offering was expected to close around September 18.

The company has undertaken a massive, 800,000m drilling programme at its flagship Windfall project in Quebec, labelling a preliminary economic assessment for the project last month "a great start".

It is also expanding its holdings at Windfall through last week's announced plan to acquire the remaining stake in Beaufield Resources which has the neighbouring Urban-Windfall project in the Abitibi belt.

Osisko shares, which have ranged between C$1.60-$5.07 over the past year, closed up 7.3% on Friday to $1.91.