CHICAGO (AP) — An investor group headed by a former Chicago alderman has submitted a bid to buy the Chicago Sun-Times.

The investors led by former Alderman Edwin Eisendrath and the Chicago Federation of Labor, an umbrella group of labor unions, submitted the bid for the Sun-Times and Reader Monday.

Terms of the offer to Wrapports LLC haven't been disclosed. Eisendrath says the investor group has raised about $15 million.

Eisendrath said the newspaper would adhere to its tradition as a voice for the working class.

Chicago-based Tronc, which owns the Chicago Tribune, the Los Angeles Times and other major newspapers, announced May 15 it had entered into a nonbinding letter of intent to acquire Wrapports.

The U.S. Justice Department asked Wrapports to extend a deadline to allow other bids.