LONDON, Nov 28 (Reuters) - The London Metal Exchange, battling a combined $472 million lawsuit from U.S. hedge funds Elliott Associates and Jane Street Global Trading, said it had a regulatory obligation to suspend and cancel nickel trades in March, according to court documents filed on Monday.

The world's oldest metals forum said its decision to cancel nickel trades on March 8 was its only appropriate option, and that subsequent analysis had reinforced that rationale, the documents showed. (Reporting by Pratima Desai and Kirstin Ridley; Editing by Jan Harvey)