diff --git a/pynxtools/dataconverter/readers/xps/README.md b/pynxtools/dataconverter/readers/xps/README.md
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--- a/pynxtools/dataconverter/readers/xps/README.md
+++ b/pynxtools/dataconverter/readers/xps/README.md
@@ -8,6 +8,7 @@ within the field of X-ray photoelectron spectroscopy into a standardized represe
 ## Supported file formats
 The reader decides which parser to use based on the file extension of the files provided. For the main XPS files, the following file extensions are supported:
 - .sle: [SpecsLabProdigy](https://www.specs-group.com/nc/specs/products/detail/prodigy/) files, propietary format of SPECS GmbH (v1.6)
+- .spe, .pro: [Phi MultiPak](https://www.phi.com/surface-analysis-equipment/genesis.html#software:multi-pak-data-reduction-software/) files, propietary format of Phi Electronics
 - .xml: SpecsLab 2files, XML format from SPECS GmbH (v1.6)
 - .vms: VAMAS files, ISO standard data transfer format ([ISO 14976](https://www.iso.org/standard/24269.html)), both in regular and irregular format
 - .xy: SpecsLabProdigy export format in XY format (including all export settings)