This paper reports on an original study designed to investigate age-related change in the way French children produce speech during oral narrative, considering both prosodic parameters -- speaking rate and duration of the prosodic speech unit -- and linguistic structure. Eighty-five French children aged four to eleven years were asked to tell a story after they were shown an excerpt from an animated film. All their remarks were transcribed and coded using "ELAN" as an annotation tool. Each narrative was analyzed for duration, articulation rate, and linguistic components (i.e., number of phonic groups, syllables, words, clauses). All measures were found to increase with age, with the duration of the phonic group and its linguistic structure showing the stronger differences. Results contribute to providing reference data on speech production during childhood, and they suggest the existence of two distinct developmental patterns in narrative production.