The number of Americans signing up for state unemployment benefits fell slightly last week but remained at a high level, the government said on Thursday in a report that suggested a still-weak labor market.

The report said first-time jobless claims dropped by a smaller-than-expected 11,000 to a seasonally adjusted 433,000 for the week ended Dec. 14, the Labor Department said.

However, the four-week moving average of claims -- a more reliable indicator of job market conditions since it smooths out wose by 12,750 to 400,750.

Economists on Wall Street had expected weekly jobless claims to fall to 408,000 from the 441,000 previously reported for the Dec. 7 week, still remaining above the key 400,000 level.

The report also showed a sharp rise in the number of Americans who remained on the benefit rolls. That figure for so-called continued claims rose to 3.50 million in the week ending Dec. 7 from 3.27 million a year earlier, the largest one-week gain since the week of Nov. 24, 1990.

Normally that would be considered a sign jobless workers were having a tougher time finding employment, but the rise followed two steep weekly drops.

The department cautioned against reading too much into the figures, saying they may reflect problems with adjusting the data for seasonal fluctuations during the November-December holiday season.

The slight fall in the four-week moving average of the continued claims suggested some recent improvement in overall labor market conditions.

"We've clearly been experiencing some seasonal adjustment difficulties and we encourage looking at the four-week moving average as a better indication of labor market conditions," a spokesman for the department said.

"It's true during all weeks of the year, but it's especially true during the holidays," he said.

The department had said previously that seasonal adjustment problems had likely pushed the initial claims figure higher for the Dec. 7 week, when claims rose by 86,000, and may have held them down in November when claims drifted lower.