Toronto, Jul 7 (IANS): Canada is reviewing the sale of Nortel patents to a foreign consortium led by Apple so that the deal is not violative of national interest.

Apple, BlackBerry maker Research In Motion (RIM), Microsoft, Ericsson, Sony and EMC bought 6,000 patents of the defunct Nortel for a whopping $4.5 billion July 1.

The Investment Canada Act mandates review of any foreign takeover of Canadian assets above $350 million to safeguard national interest.

Canadian Industry Minister Christian Paradis has reportedly sought a review of the sale to see if it is violative of the Investment Canada Act.

This is the third attempted foreign takeover of Canadian companies or assets which faces review by the government.

Last November, the Canadian government blocked the sale of the world's biggest fertilizer company - Potash Corporation of Saskatchewan (PCS) - to BHP Billiton, the Anglo-Australian mining giant, for $39 billion.

The government was also reluctant to let the London Stock Exchange take over the Toronto Stock Exchange. Before the merger deal collapsed last week, the government had announced to review it in the national interest.

The Nortel portfolio of 6,000 patents and patent applications relating to cutting-edge, next-generation wireless technology was its last remaining asset to go on the auction block.

It is the biggest sale of patents in history.

Interestingly, BlackBerry maker Research In Motion (RIM), which is now part of the consortium that has bought the patents, last year opposed the sale of Nortel's wireless assets to Ericsson on nationalist grounds.