The EPO will accelerate opposition proceedings if it is informed by the EPC or a national court or a competent authority of a contracting state that an infringement or revocation action concerning the contested patent is pending before that court or authority. The type of acceleration depends on when exactly the EPO learns of the parallel action.

The specific acceleration measures are described in the following scenarios:

During the opposition period (i.e. within nine months of the grant of the European patent):

In this case, after expiry of the opposition period, the patent proprietor is invited to comment on the opposition within three months (instead of the usual four months); the summons to oral proceedings is issued within two months of receipt of the patent proprietor's comments and summonses the parties with the shortest possible notice (Rule 115(1) EPC).

After expiry of the opposition period but before receipt of the patent proprietor's reply to the opposition:

The summons to oral proceedings shall be issued within two months of receipt of the patent proprietor's reply. The parties are summoned with as short a notice period as possible (Rule 115(1) EPC).

After receipt of the patent proprietor's reply, but before the summons:

The summons to oral proceedings shall be issued within two months of receipt of the information on the parallel proceedings. The parties are summoned with the shortest time limit (Rule 115(1) EPC).

The summons has already been issued:

The oral proceedings are brought forward to the next possible date (if this is significantly earlier).

If the decision has already been pronounced, the decision and the minutes are notified within one month.

These acceleration measures also apply with immediate effect to pending proceedings.