The United States sold a record amount of military weapons and services to foreign nations in the fiscal year just ended, according to Pentagon figures released yesterday.

The 13.6 billion total for fiscal 1978 is a record even though President Carter has pledged to reduce U.S. sales of weaponry. Administration officials said yesterday that the total is misleading because it includes such nonweaponary items as housing and hospitals.

Interpretations aside, here are the numbers released by the Pentagon for fiscal 1978, which ended at midnight Saturday:

Total sales of everything from planes to shopping-centers built under the direction of the Army Corps of Engineers, $13.6 billion - $400 million more than the previous high of $13.2 billion in fiscal 1976.

Sales of actual weapons, plus such related services as how to operate them to foreign countries except Australia, Japan, New Zealand and those in NATO. $8.515 billion. The Carter administration had set a limit of $8.551 billion for these "ceiling countries."

Sales of other military services to those "ceiling countries," $2.8 billion.

Sales of the actual weapons, plus related services, to Australia, Japan, New Zealand and NATO nations, $1.9 billion. Other military sales not considered weapons-related, about $300 million.

Weapon sales to the Mideast pushed the fiscal 1978 figure up toward the $8.551 billion ceiling, the kind of pressure that will continue to make it difficult for Carter to make good on his pledges to reduce arms sales.

Pentagon figures lumping weapons and military construction together showed that in the fiscal year that ended Saudi Aratia bought the most $4.13 billion; Iran was second at [WORD ILLEGIBLE] billion, Israel third at $1.32 billion.

The $13.6 billion total compared with $11.4 billion in total military sales for fiscal 1977.

During the 1976 campaign, Carter decried the fact that the United States was selling arms all over the world and pledged to reduce that after being elected he put the world into two categories for arms sales ceiling and nonceiling nations.

On May 19, 1977, Carter issued a policy paper on arms sales that said, in part, that "the United States will henceforth view arms transfers as an exceptional foreign policy implement to be used only in instances where it can be clearly demonstrated that the transfer contributes to our national security interests."

In that same statement, he pledged to reduce the fiscal 1978 weapons sales below those of fiscal 1977, eventually setting the ceiling that amounted to an 8 percent reduction.

His deepened involvement in the Mideast stemming from the Camp David Summit is likely to make it more difficult than ever to deny the weapons requests of Egypt and Israel in the future, thus making reductions difficult to achieve.

Although critics are expected to complain that Carter, the president who promised to reduce international arms trafficking, posted a record year in foreign sales, Lucy Wilson Benson, undersecretary for security assistance, said this would be unfair.

"He's done precisely what he said he would do," she said in stressing that the administration had stayed within the limit set for ceiling countries.