CALGARY - Former Prime Minister Brian Mulroney says Canada cannot function without foreign investment.

He made his remarks just days after Ottawa's surprise rejection of Malaysian state-owned firm Petronas' $6-billion takeover of Progress Energy Resources (TSX:PRQ).

Mulroney says the oil and gas industry needs huge amounts of foreign capital to develop, and those international relationships also allow Canadians to spend their money abroad.

While in office, Mulroney scrapped the Foreign Investment Review Agency in 1985 and brought in the Investment Canada Act — the legislation under which Petronas was rebuffed and China National Offshore Oil Co's controversial $15.1-billion takeover of Nexen Inc. (TSX:NXY) is currently being weighed.

He says the current government is giving itself some running room to adapt to changes that have taken place regarding foreign investment over the past 25 years.

Meanwhile, Mulroney didn't say which candidate he favours to win the U.S. election next month, but says Republican contender Mitt Romney will likely approve the contentious Keystone XL pipeline from the Alberta oilsands to U.S. markets right away.

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• 20: Australia

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 19: South Korea

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 18: Saudi Arabia

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 17: Belgium

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 16: Austria

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 15: Norway

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 14: Canada

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 13: Taiwan

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 12: Denmark

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 11: Qatar

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 10: Japan

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 9: Hong Kong

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 8: United Kingdom

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 7: United States

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 6: Germany

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 5: Netherlands

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 4: Sweden

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 3: Finland

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 2: Singapore

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

• 1: Switzerland

  Source: <a href="http://www3.weforum.org/docs/CSI/2012-13/GCR_Rankings_2012-13.pdf" target="_hplink">World Economic Forum</a>

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• The 10 Best Countries To Do Business

  See where Canada falls in the <a href="http://www.forbes.com/sites/kurtbadenhausen/2011/10/03/the-best-countries-for-business/" target="_hplink">Forbes rankings of the best countries in the world in which to do business</a>.

• 10. The United States

  The world's largest economy just snuck into the top 10 on Forbes' list of best countries for business. The magazine cited the nation's heavy tax burden as one of the reasons why it did not place higher. (Photo by Spencer Platt/Getty Images)

• 9. The United Kingdom

  A historic leader in global trade and finance, the United Kingdom placed a strong 9th place. (Photo by Tom Shaw/Getty Images)

• 8. Norway

  Oil boosts the economy of this Scandinavian powerhouse. (Photo by Scott Barbour/Getty Images)

• 7. Sweden

  Iconic global brands such as Ikea, Ericsson and H & M call Sweden home. (Olivier Morin/AFP/Getty Images)

• 6. Singapore

  A key global shipping hub, Singapore, is one of the best places in Asia to do business. (Roslan Rahman/AFP/Getty Images)

• 5. Denmark

  The third Scandinavian country on the list, Denmark fell from the top spot on Forbes' ranking. (Getty Images)

• 4. Ireland

  Despite being hit hard by the recent economic crisis, Ireland placed a respectable fourth on the list. (Peter Macdiarmid/Getty Images)

• 3. Hong Kong

  Home to the iconic Hang Seng index, Hong Kong's exposure to China and reliable institutions make it one of the world's best places for business. (Ed Jones/AFP/Getty Images)

• 2. New Zealand

  Punching above its weight is the southern nation of New Zealand. The country only has fewer than 4.5 million people but its the runner-up on Forbes' list. (Photo by Sandra Mu/Getty Images)

• 1. Canada

  The CN Tower looms over the Toronto Blue Jays and Detroit Tigers as the Rogers Centre's roof is open for the first time in the 2011 MLB baseball season in Toronto Saturday, May 7, 2011. (AP Photo/The Canadian Press, Darren Calabrese)