In Mexico, a third party may challenge a patent through either
an ex parte proceeding that applies to pending patent applications,
or an inter partes proceeding that applies to issued patents. Both
proceedings are held before the Mexican Institute of Industrial
Property (IMPI).
The ex parte proceeding, known as a third party observation, is
similar to the US Patent and Trademark Office’s (USPTO)
pre-issuance submissions by third parties and the World
Intellectual Property Organisation’s third-
party observations under the Patent Cooperation Treaty (which were
recently created). The legal basis for the ex parte proceeding is
Article 52bis of the Industrial Property Law, which provides for a
six month period following publication of a patent application in
the Industrial Property Gazette in which any person (it is
unnecessary to prove legal stranding) can submit any relevant prior
art information affecting the patentability of the invention in
question. In this
