The shah of Iran has told Washington he wants to spend $2 billion for 70 more F14 fighter planes, a request which puts additional strain on President Carter's effort to reduce foreign arms sales.

Government officials confirmed yesterday that the shah's request has been received but is being held up at the State Department, partly for fear of breaking through the $8.6 billion ceiling Carter has imposed for such sales to non-NATO countries in fiscal year 1978, which ends Sept. 30.

Although that ceiling is not in danger of being broken at the moment, with $4.3 billion in arms deals charged against it to date, a last-minute flurry fo sales between now and Sept. 30 is expected to push the total near it - even without the F14 sale to Iran.

The president has said that his policy "is to reduce the level of arms sales in each succeeding year . . . We are determined to begin a downward trend in the sale of weapons throughout the world."

The shah's latest request for F14s is one reason the lower ceilings Carter has promised for future years are in jeopardy. The shah's wish list for U.S. weaponry is a long one that goes far beyond aircraft.

Next month an administration delegation headed by David E. McGiffert, assistant secretary of defense for international security affairs, is expected to travel to Iran to review the Shah's wish list of weapons.

Although the president would like to make good on his pledges to reduce arms sales abroad, the shah has considerable political leverage because of his influence over international oil policies. Also, the United States wants Iran's money to offset the higher price of oil.

Domestic political pressure for selling the Shah more F14s stems in part from the fact that Grumman Aerospace Corp. of Long Island, manufacturer of the plane, is hurting for new business. The 79th of the 80 F14s previously ordered by the shah was flown from the plant to Iran on Wednesday. The New York congressional delegation is expected to press Carter to approve the shah's new order to save jobs at Grumman.

One idea discussed within the Carter administration is to approve the shah's request but stretch the sale of the F14s over four years to reduce the amount that would have to be charged against the arms export ceiling in any one year.

Aerospace sources said yesterday that administration officials have told them not to expect the F14 or any other multibillion-dollar deal to be submitted to Congress this year - that they must wait until at least February.

President Nixon decided to sell the shah the Navy's F14 Tomcat.His decision upset some weapons specialists who argued the plane is too sophisticated for Iran.

The F14 is armed with six Phoenix missiles, each of which can track and hit a separate airplane or missile from over 100 miles away. The shah, military sources said, sees the plane as a way to stop Soviet overflights of Iran.