Oceanspan Carriers Ltd. v. The Queen, 87 DTC 5102, [1987] 1 CTC 210 (FCA) -- summary under Paragraph 111(1)(a)

"A corporation which incurs losses from business activities outside Canada when it is neither a resident nor had income from a source in Canada, and thus is not subject to assessment under the Act, is not entitled to deduct such losses to reduce taxable income to nil on income derived after it becomes a Canadian resident."