Burger King restaurant in Baltimore, MD; Photo: Diego M. Radzinschi/ALM

U.S. fast-food giant Burger King has lost a long-running trademark infringement dispute against a small burger chain in India, allowing the underdog to keep its royal name.

India's law office Adv Abhijit Sarwate described the judgment in favour of their client as "a hard-fought victory achieved after 13 years of persistence, planning and crafty cross-examination".