PORTLAND – The Portland Newspaper Guild announced Friday that it has launched an exploratory effort to make a bid for local employee ownership of the Blethen Maine Newspapers and Web sites following the Seattle Times Co. announcement last month that it was offering all of its Maine properties for sale.

The Portland Press Herald-Maine Sunday Telegram, Kennebec Journal of Augusta, Morning Sentinel of Waterville and MaineToday.com, which combined have more than 600 employees, are being sold.

The union has retained the consulting firm Ownership Associates Inc. of Cambridge, Mass., to advise the employees in the deal. The president of Ownership Associates, Christopher Mackin, has 30 years of professional experience in the area of employee ownership.