With several media outlets reporting that a deal is near for Dean Singleton to buy Knight Ridder’s Northern California newspapers, state Attorney General Bill Lockyer says he will investigate whether the transaction will reduce competition. The U.S. Department of Justice is conducting a separate investigation. The Central Valley Business Times quotes Lockyer, a Democrat, as saying he wants to know if the reduction in competition would be significant enough to warrant intervention. The deal will give Singleton’s MediaNews two newspapers in Alameda, San Mateo and Pleasanton, and it’s unlikely he will keep two papers in each town. The deal will also give Singleton a Bay Area circulation of more than 800,000 copies a day, twice that of the Chronicle. Singleton already owns the Oakland Tribune, San Mateo County Times, Marin Independent Journal, Hayward Daily Review, Alameda Times-Star, Fremont Argus, Vacaville Reporter and Vallejo Times-Herald. He hopes to buy the San Jose Mercury News, Contra Costa Times, Palo Alto Daily News Group (including papers in San Mateo, Burlingame, Redwood City, Berkeley and Los Gatos) and the Monterey Herald. He will also get weekly newspaper groups in Santa Clara County and Alameda County.