The nation's unemployment rate edged downward in February to 7.3 percent while sharply rising energy costs helped keep producer prices for finished goods increasing at double-digit rates; the Labor Department reported yesterday.

Prices for finished goods increased 0.8 percent, or at a 10 percent annual rate, despite a 0.6 percent drop in consumer food prices. Prices for home heating oil jumped 6 1/2 percent from January, while those for gasoline rose 4.7 percent.

However, Janet L. Norwood, commissioner of labor statistics, told Congress' Joint Economic Committee that most of the price increases in petroleum products that have occurred since President Reagan decontrolled crude-oil prices late in January were not included in the figures released yesterday. Thus, they will be picked up in the March producer price index data.

Norwood said the country's overall employment situation was little changed in February even though the unemployment rate dropped one-tenth of a point from the 7.4 percent rate of December and January. Total employment rose by 231,000 to 97,927 million, with the average for the first two months of the year running about 500,000 jobs above the level of the fourth quarter of 1980 she said.

The length of the average factory work week dropped by an unusually large six-tenths of an hour, but Norwood explained, "It is difficult to evaluate the importance of this decline since the data were affected by the extremely bad weather conditions during the survey . . . week in the heavy manufacturing areas of the Midwest and Central United States."

During a separate part of the JEC hearing, Labor Secretary Robert J. Donovan defended the planned cutbacks in spending for public-service jobs as a necessary part of the administration's economic revitalization program.

But Donovan added candidly, "I am not here to say there is anything other than pain and sacrifice here. . . . I could not call these cuts particularly humane. I am not here to say they are."

Nevertheless, the Labor secretary labeled as "not impressive" statistics about the ability of minority and handicapped individuals to get private-sector jobs once their public-service jobs are wiped out by the administration's budget cuts. The purpose of the entire program was to provide training for the so-called structurally unemployed, and it has not done so, he said. "Public-service employment is not a training program," he declared.

The committee chairman, Rep. Henry Reuss (D-Wis.), and Rep. Parren Mitchell (D-Md.) both pressed Donovan on the point that eliminating the federally financed jobs could worsen unemployment. Donovan acknowledged that it would but argued that the administration's overall program would add jobs, probably within a year.

"I absolutely would have gone down with the ship on the question of public-service employment if there hadn't been a meaningful program" to generate more jobs in the private sector, Donovan said.

According to the Labor Department, the jobless rate for adult men was 6 percent last month, unchanged from January. The rate for adult women fell from 6.7 percent to 6 1/2 percent. The unemployment rate for teenagers rose from 19 percent to 19.3 percent, and the rate for blacks and other minorities increased by 0.2 percentage point to 13.1 percent.

The department's hourly earnings index rose 1/2 percent last month, considerably less than in January, but the index was still up 9 1/2 percent in the last 12 months. The index increased 0.9 percent in January.

After virtually no increase in the preceding three months and the 0.6 percent decline in February, prices for finished consumer food have helped offset much of the impact of sharply rising energy prices. However, most experts say food prices will resume their steady march upward soon and that retail food prices may be up 12 percent this year from 1980 levels.

For goods at earlier stages of processing, the price news was good except on the energy front. The price index for crude materials rose 2.9 percent, almost entirely because of the jump in crude-oil prices as other materials prices generally continued to move down. At the intermediate level, price moderation was evident in a wide variety of industrial goods, and prices for foods and feeds decreased, the department said.

Separately, the Federal Reserve said consumer credit outstanding rose a seasonally adjusted $869 million in January, an increase at a 3 percent annual rate. The January rise followed a $1.62 billion increase the month before.

Also, the Federal Reserve said the money supply measure known as M-1A, which includes currency in circulation and checking account deposits at commercial banks, fell $1.8 billion in the week ended Feb. 25 to a level of $364.9 billion. M-1B, which also includes checking deposits at other financial institutions, fell $1.3 billion to a level of $417 billion.