President Reagan has decided to postpone any new economic sanctions against the Soviet Union until an administration team consults with the European allies on a variety of East-West issues, a State Department spokesman announced yesterday.

Spokesman Dean Fischer said that the purpose of the consultations will be to work out a "coordinated policy," including a joint approach to such issues as future commercial credits to the Soviet Union, a matter that has been receiving increasing attention within the administration.

Reagan met with advisers last Friday to discuss a range of possible sanctions to force a relaxation of Polish martial law, but he withheld a decision on new steps. The postponement announced yesterday appeared to signify acceptance of the view of Secretary of State Alexander M. Haig Jr. that broad alliance support and careful preparation are essential if any sanctions are to succeed.

Officials at the National Security Council and the Defense Department have argued for an all-out effort to delay the construction of the Urengoi natural gas pipeline from western Siberia to Europe, even at the risk of angering allied governments heavily committed to supplying pipeline equipment and taking back energy.

On Dec. 29 the president, citing Soviet responsibility for repression in Poland, banned the sale of American-made turbine parts and pipe layers for the project. One option under study is an extension of these trade controls to European companies licensed by U.S. firms--a step certain to provoke sharp controversy within the alliance.

Applying such extraterritorial controls was strongly opposed yesterday by two Republican senators, Charles McC. Mathias Jr. of Maryland and Charles H. Percy of Illinois. During a hearing of the Senate Foreign Relations subcommittee on international economic policy, Mathias warned that such a unilateral U.S. action would set back efforts to enlist European help in tightening restrictions on the sale of strategic technology to the Soviets, which is another priority of the Reagan administration.

At the same hearing Washington attorney Stanley Marcus, noting that the U.S. licensing arrangements with European companies date back a number of years, questioned the legality of government interference in the activities of overseas firms with long-standing agreements to use American technology.

As a result of the impasse between the United States and the European allies on the sanctions issue, officials here are focusing on the possibility of credit restrictions against the Soviets. Toughening credit terms for future East-West deals has appeal at both the State and Defense departments. Officials here say it would also meet allied objections to trade bans, which hurt European economies more than the United States.

U.S. officials contend that West European banks and governments have, in effect, subsidized the Soviet bloc by extending soft, government-guaranteed loans.

Analysts say western credit restrictions would pose real economic problems for the Soviet bloc. For example, the Soviet Union and its allies now have some $4 billion in commercial bank loans which are regularly "rolled over," or refinanced. A refusal to roll over these loans would create a credit squeeze.

In addition, $14 billion is owed on short-term trade credits coming due in less than a year. Future removal of the government guarantees that stand behind many of these credits could create severe financial problems, according to analysts.