Oman will look after Iranian affairs in Canada after diplomatic relations were suspended last year, Iran said on Tuesday, part of efforts by Tehran to improve ties with the West under President Hassan Rouhani.
Canada closed its embassy in Tehran and expelled Iranian diplomats in Canada in 2012. Canadian Foreign Minister John Baird at the time called Iran the biggest threat to global security.
Rouhani is trying to mend ties with Western nations to try to win the removal of economic sanctions imposed over Tehran's disputed nuclear programme.
"Oman has been named the protector of Iran's interests in Canada, and Italy has been named the protector of Canada's interests in Tehran," Foreign Ministry Spokeswoman Marzieh Afkham said, according to the ISNA news agency.
"This act took place after political correspondence and notes between the representatives of Iran and Canada were exchanged at the United Nations."
Canada's Conservative government has long had poor relations with Iran, enemy of Canadian ally Israel.
Canada's move to cut ties with Iran came after Britain's embassy in Tehran was stormed by protesters in 2011 and then closed
Britain and Iran said last month they would appoint non-resident diplomats and have said they are in talks to restore diplomatic relations.