MDS Inc. is suing Atomic Energy of Canada Ltd. and the federal government, seeking $1.6 billion over the cancellation of the MAPLE reactor project.

The Toronto-based company, a major supplier of nuclear medicine isotopes, said Wednesday it has served AECL with notice that it is seeking arbitration, and at the same time has filed suit alleging negligence and breach of contract. The company’s parallel litigation against the government alleges inducement to break a contract and interference with economic relations.