Production at the Miro joint venture's 310,000 b/d Karlsruhe refinery has been restricted by a failure today at a crude distillation unit (CDU).
A supplier expects this to result in a multi-week reduction in spot supply from the refinery.
The shutdown of a production line at the plant, which is located on the Rhine river in southwest Germany, has led to an estimated 30pc reduction in products output. At least one supplier has fully suspended spot offerings for heating oil and road fuels.
Trains and barges that were planned for transporting from the refinery have been canceled, although pick up of contracted volumes is unaffected.
Sources said the facility should be back in operation in the coming weeks. Miro did not respond to a request for comment.
Production in southern Germany is already constrained after a fire shut the Neustadt section of the Bayernoil consortium's 215,000 b/d Vohburg-Neustadt refinery.
