Statistical techniques and grammatical inference have been used for dealing with automatic speech recognition with success, and can also be used for speech-to-speech machine translation. In this paper, new advances on a method for finite-state transducer inference are presented. This method has been tested experimentally in a speech-input translation task using a recognizer that allows a flexible use of models by means of efficient algorithms for on-the-fly transducer composition. These are the first reported results of a speech-to-speech translation task involving European Portuguese input that we know of.