The prints of Gladiator were Dolby EX and the DTS discs were ES. EX and ES theatrically are 6.1 but use matrix encoding to get the 6th channel. No discrete center surround on 35mm. Source:
http://www.film-tech.com/ubb/f1/t000919.html
The DVD of Gladiator has a discrete DTS 6.1 track.