European Patent Opposition Statistics for 2005

According to James Wilding and Andy Bridle writing for Managing Intellectual Property, oppositions were filed against 5.4% of granted patents in Europe in 2005:

• Of the 2,330 opposition cases decided at first instance in 2005, patent revocation was ordered in about 38% of cases,
• maintenance of the patent in amended form was ordered in about 32% of cases, and
• the opposition was rejected in about 30% of cases.
• Appeals were filed against 943 decisions by the Opposition Division in 2005
• The average duration of appeal proceedings pursuant to inter partes disputes before the EPO in 2005 was 31 months.

"It is relatively inexpensive to file an opposition," they write, "but it can have the effect of removing a patent which blocks a technology area of interest, restricting the scope of an overly broad patent or simply provoking licensing discussions with the patentee."