MONTREAL - Shares in Osisko Gold Royalties Ltd. fell by almost 10 per cent Monday after it announced a deal to buy the shares of Barkerville Gold Mines Ltd. it doesn't already own.

Osisko, which has a 32.6 per cent stake in Barkerville, says the deal will give it a larger role in advancing and developing Barkerville's Cariboo gold project in British Columbia.

The Montreal-based mining company also announced it was creating the North Spirit Discovery Group to privatize and surface value in resource development projects.

Osisko shares slipped to as little as $14.67 from Friday's close of $16.26 after it announced it would issue 0.0357 of a common share of Osisko for each Barkerville share. Barkerville shares rose by as much as 21.7 per cent to 56 cents before drifting lower.

Osisko says the ratio implies a value of 58 cents per Barkerville share, representing a 44 per cent premium based on both companies' trailing 20-day volume weighted average price, thus valuing Barkerville at $338 million.

Analyst Andrew Kaip of BMO Capital Markets says the deal is accretive but it increases risk by adding a project developer role for Osisko.