Genstar accepted a sweetened bid from Imasco.

Although Genstar said it has accepted the $1.69-billion offer from Imasco Ltd., the companies also agreed to first negotiate the possibility of Imasco acquiring only Genstar’s financial services unit, Canada Trustco Mortgage. If those talks are not successful by April 15, then Imasco would buy all of Genstar. While its executives offices are in San Francisco, Genstar is a Canadian company that also has interests in building materials and land development. Montreal-based Imasco owns Imperial Tobacco, Canada’s largest cigarette producer, and its U.S. holdings include Hardee’s fast-food restaurants and Peoples Drug Stores.