Bonn — Bonn regards Washington's extension of export sanctions on the Soviet Union to cover European as well as American firms as a political blunder.
It regards Washington's decision, however, as reversible in practice and as less important than the alliance unity that has recently come together over the key issue of arms control.
The West German government's main concern at the moment, therefore, is to play down the embargo blunder and prevent it from dissipating the considerable good will generated by President Reagan's visit to Europe this month. In particular, it wants to avert a major row between the United States and France, whose economy is most affected by the current transatlantic trade disputes.
This interpretation of Chancellor Helmut Schmidt's formal foreign policy declaration to the Bundestag June 24 emerges from conversations with senior West German and American officials here.
They were discussing Schmidt's criticism of the sudden June 18 Reagan administration decision to apply extraterritoriality to the US ban on sale of gas pipeline compressors to the Soviet Union. The ban, instituted to penalize the Soviet Union after Poland's declaration of martial law last December, has now been applied to overseas holders of US licenses as well as to American exporters themselves - and it has raised a storm of protest in Europe.
Some of the sharpest criticism has come from French President Francois Mitterrand, whose new austerity program and franc devaluation are being undermined by American-European economic feuds. Reports out of Paris speak of ''hypocrisy'' in the US failure even to inform its European allies about the impending move during Reagan's various economic and other summits in Europe earlier this month.
The French economy is hit not only by the compressor embargo, but also by the US suit against European steel firms under old protectionist laws, and by the sky-high US interest rates.
Schmidt repeated some of this criticism in his Bundestag speech, and quoted the just-passed European Community resolution calling the US embargo decision illegal and ''unacceptable.'' He also made it clear that Europeans will proceed with the Soviet pipeline deal even if it is delayed for lack of the American-licensed parts. He did not mention the steel dispute, however, and he said very little about high US interest rates.
Informed sources now say that what Bonn hopes for is gradual softening of the application of the embargo. That way, the ill will generated by the move could be reduced.