A Regina lawyer has launched class-action lawsuits against Conrad Black , his wife and associates, seeking at least $4 billion for shareholders in the newspaper magnate's companies.

No dollar figure has been fixed, but the cases seek to recover market losses, lawyer Tony Merchant said in a release. The cases were filed in Saskatchewan and Ontario on Tuesday.

He said he expects the courts will allow the class to include shareholders in Hollinger Inc., a holding company, and Hollinger International Inc., a newspaper publisher. Black controls Hollinger Inc., which controls Hollinger International.

The shareholders Merchant seeks to include in the group range from small investors to pension, insurance and mutual-fund companies.

The drop in the stock-market value of the Hollinger companies may be linked to the controversies involving Black's management and allegations he and associates took hundreds of millions of dollars they weren't entitled to.

Black and his associates reject the allegations.

Hollinger Inc. and other related Lord Black companies are located in Canada and "many of the questionable transactions" took place in Canada, Merchant said.

Saskatchewan allows quick court access. "Early protection of shareholder rights may be profoundly significant if these companies experience ongoing negative pressure as further discoveries of wrongdoing emerge," Merchant said.