1. An opposition division enlarged to four members pursuant to Article 19(2) EPC 1973 can in principle be reduced again to three members. It is for the four-person panel to decide on the reduction. In this respect the board concurs with T 990/06. In deciding on the reduction, the opposition division consisting of four members must properly exercise its discretion. (See point 1.4)

2. The board assumes arguendo that the fact that no decision to enlarge nor a decision to reduce the opposition division was added to the publicly available file and the fact that the appointment of the new chairman could only be traced from the internal register of the EPO both constitute fundamental deficiencies of the proceedings before the opposition division.

However, different from the situation in T 990/06, it is possible to determine from the file that the division was lawfully enlarged and, at a later stage, lawfully reduced again. (See points 1.6 and 1.7)

The board considers that these circumstances constitute special reasons for not remitting the case within the meaning of Article 11 RPBA. The aforementioned fundamental deficiencies assumed arguendo are of a formal nature. They would, in the board's view, not justify substantially delaying the proceedings. (See point 1.9)