Right, Warner Brothers owns the North American rights to JOURNEY INTO FEAR...although I have no idea who would handle the film rental.
As you may or may not be aware of, there are two versions of the film which exist. The one most commonly seen in the U.S. is the version released in February, 1943 which Welles himself did a quick re-edit of, shooting a new ending scene and adding a narration by Joseph Cotten's character. However, an earlier version of the film (released briefly in August, 1942) has been shown in Europe which contains additional footage, no narration and a different concluding scene. Unfortunately, neither of these versions is ideal. The August '42 release is a studio bastardization of Norman Foster's initial 91 minute preview cut that wrecked havoc with the continuity. However, this version does contain a bit more comedy and includes a scene with Welles' "Col. Haki" that is not in the other extant version. Welles' "final" cut (released Feb. '43) is an attempt to refashion the Aug. '42 bastardized version with middling results.