For the 12th week in a row, initial claims for unemployment benefits in the U.S. were above 400,000 last week, the Labor Department said. The seasonally adjusted figure fell slightly, to 428,000. The four-week average has remained at 426,000 for a month, the department said. The economy needs at least 125,000 new jobs a month just to keep up with population growth. At least twice that many jobs are needed to lower the unemployment rate.