Continued massive job losses in the oil and manufacturing industries pushed the nation's civilian unemployment rate up from 7.1 to 7.3 percent in May and weakened prospects of an economic rebound soon.

The number of Americans out of work rose by 212,000 last month to nearly 8.6 million, putting the unemployment rate back up to levels of last February, according to the Labor Department's survey of households.

Many economists still expect improvement in the economy later this summer as consumers begin to realize that lower inflation has given them more money to spend. Their optimistic outlook is based in part on recent gains in the government's index of leading economic indicators, which is designed to forecast economic activity several months in advance.

But other economists have begun to discount the reliability of the leading index, saying that most of the indicators that have been pointing toward improvement are financial -- such as higher stock prices -- and do not reflect the underlying weakness in manufacturing and the fact that growth is coming in low-paying services jobs.

"The unemployment numbers show an economy with a split personality," said Jerry Jasinowski, chief economist for the National Association of Manufacturers. "There's a booming services sector and massive increases in employment. On the other hand, energy, farming and durable-goods economies are flat on their backs. We're not going to get a . . . rebound if the economy remains neurotic."

The unemployment rate, including members of the armed forces stationed in the United States, increased last month from 7 percent to 7.2 percent.

The steep decline in oil prices since last fall was expected to boost economic growth as it reduced costs for businesses and left consumers with more money in their pockets.

The oil price drop has been credited in the past few months for the nation's best record on inflation in decades. That, in turn, has helped bring down interest rates, which has boosted home sales to record levels and contributed to job gains in insurance, finance and real estate.

But falling oil prices have had negative effects as well. The shutdown in many now-unprofitable oil operations has eliminated 100,000 jobs in the energy industry and thousands more in related fields. The oil price decline also has prompted drastic cutbacks in plans for business investment this year.

"The most dramatic employment decline continued to be in oil and gas extraction, where May declines of almost 30,000 pushed the losses so far this year to nearly 100,000," Janet L. Norwood, commissioner of the Bureau of Labor Statistics, said.

In January, there were 556,000 employed in oil and gas extraction. Last month, that dropped to 461,000.

"Weakness in this industry has affected other industries as well," Norwood said. "Oil field machinery manufacturing, for example, lost about a quarter of its jobs over the past year, much of that in the past few months."

Manufacturers -- buffeted by import competition and still relatively high consumer interest rates -- lost 40,000 jobs last month, bringing the total jobs lost this year to 100,000. In less than two years, 300,000 jobs at factories have disappeared, Labor said.

While some economists said that the erosion of jobs means that Americans will have less income to spend on goods, thus threatening a rebound in economic growth, others said that unemployment figures tend to reflect what happened in the economy late last year and don't necessarily mean that economic activity will not accelerate in the next few months.

Allen Sinai, chief economist for Shearson Lehman Brothers, said that the increased unemployment rate reflects more the weakness in the economy last year "and the continuing problems in manufacturing and mining than giving us a reading on the prospects of a rebound of growth in the second half of the year."

Sinai said that what is more significant is increased spending on housing and automobiles. "It is those areas that typically lead generalized expansion in the U.S. economy," he commented.

"It is not impossible that the economy may be picking up at the same time that employment is declining," said Lawrence Chimerine, of Chase Econometrics.

However, he added, "It's much too premature to suggest that a rebound is about to happen. It's probably at least a couple of months away."

Manufacturers of durable goods -- items expected to last more than three years, such as furniture and major appliances -- are hurting the most, possibly because consumers need to purchase them on credit, Jasinowski said. Consumers have high debt loads, and interest rates on credit purchases are still relatively high, he said.

Additionally, consumers already may be saturated with these goods, which they purchased in large numbers during the beginning of the economic recovery. "Who needs three microwaves?" Jasinowski asked.

The auto industry lost 15,000 jobs in May, bringing the total lost since early last year to 50,000, Labor said. The auto industry is reducing its work force because of increased use of robots and computers and more competition from imports, economists said.

The jobless rate for men rose from 6 to 6.4 percent, reflecting the weakness in the manufacturing industry. The rate for women increased from 6.4 to 6.5 percent. The rate for teen-agers dropped from 19.6 to 19 percent.

The rate for whites rose from 6.1 to 6.2 percent and the rate for blacks was unchanged at 14.8 percent. The rate for Hispanics rose from 10.4 to 11 percent.

"The May increase leaves unemployment stuck in the same 7 to 7.5 percent range that has prevailed for two years now," said Rudy Oswald, chief economist for the AFL-CIO. "In the postwar era prior to 1980, this level was only surpassed in the recession in 1975."