Corporate profits plunged sharply during the first three months of this year, the government reported yesterday, but analysts said the drop stemmed mainly from the cold weather and the coal strike, and probably will be made up this quarter.

New Commerce Department figures show that profits from current production - the earnings measure economists regard as most significant - fell 12.4 percent between January and March following a 2.8 percent increase in the final three months of 1977.

At the same time, the department said revised figures showed the "real" gross national product - or actual volume of the nation's output - declined at only an 0.4 percent annual rate during the period rather than the 0.6 percent pace reported previously.

Although yesterday's figures showed a slightly smaller decline than first estimated, the report essentially confirmed preliminary statistics published last month. The GNP price index showed inflation rising to a 6.7 percent annual rate, revised from 7 percent earlier.

Meanwhile, Robert Strauss, President Carter's new anti-inflation czar, disclosed that the administration finally is beginning to carry out the plan Carter announced in April to use government purchasing power to help hold down prices.

In a special appearance at the White House, Strauss said the program will include delaying purchases of goods for which prices are rising too rapidly, searching for less expensive substitutes, and tightening cost-escalator clauses in federal contracts.

He also said Carter is establishing a special "small, high-level" task force on government efficiency that will seek to reduce waste in federal programs and regulations. Strauss predicted continued gloomy inflation news for the next two months, followed by some improvement.

The drop in corporate profits marked one of the few adverse economic reports recently in the midst of generally good news on other fronts. The decline stemmed mainly from employment increasing as output - boosting unit labor costs declined.

The dip in profits from current production amounted to $18 billion in dollar terms, bringing profits to a new seasonally adjusted annual rate of $126.8 billion. Profits from current production are regarded as likely to provide the most accurate picture of business health.