By John S. McClenahen Initial claims for unemployment insurance last week fell to 345,000, a decline of 7,000 from the previous week's revised figure of 352,000, the U.S. Labor Department reported on March 4. The department's four-week moving average of initial claims, generally regarded as a better indicator of the U.S. labor market's basic condition, also decreased during the week ending Feb. 28. It fell by 3,000 to 352,250. On March 4, the Labor Department also posted final productivity numbers for both the fourth quarter of 2003 and the full year. The new data show that while fourth-quarter 2003 productivity in the nonfarm business sector of the U.S. economy grew at a seasonally adjusted annual rate of 2.6%, a tenth of a percentage point less than first figured, full-year productivity advanced at a 4.4% rate, two-tenths of a percentage point higher than initially calculated. Productivity among manufacturers grew at an annual rate of 4.8% in last year's October-through-December quarter, the same figure originally reported. But the Labor Department revised manufacturing's full-year gain upward to 5.1% from 4.3%.