The number of U.S. workers filing new claims for jobless benefits rose 27,000 last week, the government said on a report on Thursday that showed the number of workers receiving benefits at a record high.

Initial claims for state unemployment insurance benefits increased to a seasonally adjusted 640,000 in the week ended April 18 from a revised 613,000 the prior week, the Labor Department said.

Analysts polled by Reuters had forecast 635,000 new claims versus a previously reported count of 610,000 the week before.

However, the number of people claiming benefits after drawing an initial week of aid advanced 93,000 to a more-than-forecast 6.137 million in the week ended April 11, the most recent week for which data is available.

It was the highest reading of so-called continued claims on record and the fourteenth consecutive week that this measure had increased. Analysts forecast continued claims would be 6.12 million.

The country's most severe recession in a generation has cost more than 5 million jobs since it began in late 2007 and economists fear this toll will keep rising as businesses slash payrolls to protect profits.

U.S. stock index futures pared gains after the data and U.S. government bond prices moved up from earlier lows.

After the unexpected Easter-related drop in claims last week we expected a bigger rebound, taking claims back to their highs of around 670,000, said Ian Shepherdson, chief U.S. economist at High Frequency Economics.

The failure to rise that high suggests either that the trend in claims is peaking or that the data are still affected by seasonal problems related to the holiday. We are inclined to take the latter view, he said.

The rise in continued claims pushed the uninsured unemployment rate to 4.6 percent from 4.5 percent the week before, the highest rate since January 1983.

A Labor Department official said there were no special factors affecting the data.

The four-week average of new jobless claims, a better gauge of underlying labor trends because it irons out week-to-week volatility, declined somewhat to 646,750 from 651,000 the week before, but remained at elevated levels.

(Reporting by Alister Bull, Editing by Neil Stempleman)