WASHINGTON — The number of American workers filing new jobless benefit claims unexpectedly jumped above 600,000 last week to a fresh 26-year high, signaling that the nation's recession is widening and deepening.

Separately, U.S. productivity growth -- a measure of how much workers produce per hour of labor -- more than doubled between the July-through-September quarter and the final three months of the year. But instead of seeing the data as evidence of improvement, analysts said the jump from an annual average of 1.5% to 3.2% was yet another sign of trouble.

In essence, companies reacted to the economy's sharp contraction by cutting workers at a faster pace than output, making it appear that those who remained on the job were growing more efficient.

The latest economic soundings bode ill for today's January jobs report, which many forecasters now say could show a monthly loss of 500,000 or more positions.