McDermott Will & Emery has gone to court to compel arbitration with its New York landlord over a real estate tax disagreement, saying the amount in dispute could be more than $16 million over the life of its lease.

According to the Thursday petition, landlord 340 Madison Fee LLC, has demanded $1.04 million in additional rent based on tax escalation adjustments and charges calculated and claimed by the landlord. The firm disputed the recalculation of the base tax amount and charges, and negotiations to resolve the dispute have failed. The firm said it paid more than $1 million in disputed funds as a sign of good faith, but the landlord has refused to arbitrate, "thus seeking a multi-million dollar windfall without any adjudication."