The Joint Research Centre of the European Communities has published an open invitation to tender for the supply of a mass spectrometer. The Commission intends to purchase an isotope mass spectrometer possessing the following characteristics: - Thermal ionization source; - High sensitivity; - Multicollector; - Ability to measure, simultaneously, the two groups for masses: 223, 234, 235, 236, 238; and 235, 238, 239, 240, 241, 243, 244; - Ability to measure, using the "peak-jump" method, the isotopes of elements Li, B, Mg, K, Ca, Rb, Sr, Re of the lanthanides and actinides. Requests for tender specifications should be sent to: European Commission Institute for Transuranic Elements Postfach 2340 D-76125 Karlsruhe. Tel. +49-72479510; Fax +49-7247-951590 Completed tenders should be sent to the same address.