The U.S. government reported yesterday that the nations of the world spent more than $750,000 a minute for military purposes in 1976.

The $400 billion total, the U.S. Arms Control and Disarmament Agency said in its 168-page report, was 2 1/2 times the amount the world spent on public health.

The United States and Soviet Union, the report said, accounted for two-thirds of the weapons exported to other nations, with the Middle East the biggest customer. The United States exported 39 percent of the arms sold abroad and the Soviet Union 28 percent.

The brawling in Africa is manifested in the report by sharp increases in weapons imports by countries there. African military expenditures climbed from $1.4 billion in 1967 to $5.9 billion in 1976.

The $5.9 billion spent for military purposes by African countries compares with an Arms Control and Disarmament Agency estimate that they spent $2.5 billion for public health and $5.3 billion for education.

"In general," the ACDA report said, "military expenditures increased in almost all regions of the world throughout the 1967-76 period, even after the adjustment for inflation," continuing the upward trend registered since the end of World War II.

President Carter has decried the increasing worldwide arms trade and has set dollar ceilings in hopes of reducing U.S. weapons exports. It is too early to know if he will succeed, however.

The latest accounting by ACDA covers through 1976, before Carter took office, and contains these other findings:

U.S. military spending, after allowing for inflation, dropped from $120 billion in 1967 to $86.7 billion in real terms in 1976, while public health spending rose from $25.1 billion to $56 billion.

Soviet military expenditures, in totals adjusted for inflation, rose from $79.2 billion to $121 billion in that same 10-year period, while public health spending increased from $14.2 billion in 1967 to $22.6 billion in 1976.

Despite its drop in military spending between 1967 and 1976, the United States increased sales of weapons abroad from $3.5 billion to $4.9 billion in that period, even after allowing for inflation.

The Soviet Union's arms exports went up in the same 10-year period from $3 billion to $3.5 billion, in adjusted dollars.

Paul C. Warnke, ACDA director, said the report was prepared to "stimulate informed attention" on the growing arms trade and to draw attention "to the opportunities for arms control. . . ."

The report said the $400 billion spent in 1976 was a 3 percent increase over the previous year after allowing for inflation.