Lawsuits tied to the accounting irregularities include those in Canada and a class action lawsuit in the United States .
Penn West notified Canadian and U.S. regulators about the irregularities and expanded their own investigation to review results going back to 2007 .
Lawsuits tied to the accounting irregularities include those in Canadian and a class action lawsuit in the U.S.   .
Penn West notified Canadian and U.S. regulators about the irregularities and expanded their own investigation to review results going back to 2007 .