Namco Bandai has filed a trademark for 'Soulcalibur: Lost Swords', hinting at the possibility of an unannounced Soulcalibur title being in the works at Project Soul.

According to the United States Patent & Trademark Office, the publisher registered the trademark last Thursday - the same day it registered a trademark for Ace Combat: Infinity.

The last title in the acclaimed fighting series, Soulcalibur V, released in February 2012. has contacted Namco Bandai for comment.