Sentry also alleged last year that Timmins was not receptive enough to interest shown by potential buyers.
Timmins says it is positioning itself as an “emerging intermediate, Mexican-focused gold producer.”
Its assets include the San Francisco open-pit mine in the state of Sonora as well as recently acquired gold projects in Caballo Blanco and Ana Paula.
Officials at Sentry did not immediately respond to requests for comment.
RBC Dominion Securities analyst Sam Crittenden said in a research note Tuesday that the leadership change and impairment charge add up to a negative for the company.
Timmins Gold had already announced technical problems at its San Francisco site and lowered its 2015 production guidance while raising its cash cost forecast due to lower grades at the mine, Mr. Crittenden said.
Mr. Bragagnolo, a Vancouver lawyer, founded Timmins with current president Arturo Bonillas.
Timmins said on Tuesday that Anthony Hawkshaw, the chairman of the finance committee, will provide consulting services to the company “in its efforts to improve its financial position and seek new capital for project developments.”
The company is also reviewing the carrying value of its assets and “anticipates that it will incur a significant impairment charge” for the quarter ended Sept. 30.
The price of the yellow metal – usually viewed as a safe-haven asset – is currently around $1,140 (U.S.) per ounce, a 40-per-cent drop from its 2011 peak.
Follow Bertrand Marotte on Twitter: @globemontreal