89Where an activity, business, trade or undertaking is disposed of, transferred or sold in any manner or amalgamated, whether by agreement, will, instrument, transfer, including transfer of shares, or by operation of law, the period of employment of an employee of the activity, business, trade or undertaking at the time of such disposition, transfer, sale or amalgamation, shall be deemed to have been a period of employment with the disposee, transferee, purchaser or amalgamation and the continuity of employment shall be deemed to be unbroken.