However, Kerger refused to disclose any plot details, including whether Shirley MacLaine would return as a newly introduced American relative to the Crawley family.
Head of PBS, Paula Kerger said putting Downton up against the big hitters of the competitive US autumn TV season may not have served the show or its audience.
Kerger described the ratings as "a beautiful thing", but added that it would be interesting to see how the audience responds to the show as it continues its run.