In this study we examine phonetic variation of discourse markers in French, using for this purpose the4-hour richly annotated LOCAS-F corpus. Both linguistic factors and stylistic variables are considered:speech style, part-of-speech category, mean phone duration and vowel formant distributions with respect tothe word status. The results show that the use of discourse markers increases with the degree of spontaneity of the speech. Coordinating conjunctions are thepart-of-speech which is most frequently used for discourse markers. Moreover, the mean phone durationtends to be shorter and the vowel space more centralized when words are employed as discourse markers,suggesting that discourse markers undergo hypoarticulation and, more generally, reduction.