OTTAWA - Concerns and questions are emerging from the heart of the oilpatch over the federal government's new foreign investment framework, with some business groups and the Alberta government seeking more clarity around the updated rules and what they mean to future transactions.

The Conservatives are also facing mounting criticism from opposition parties that are demanding the government release the terms and conditions applied to the CNOOC and Petronas takeovers of Canadian petroleum producers Nexen and Progress Energy Resources.

The Harper government, however, maintains it must reserve discretion on determining what investments are of "net benefit" to Canada - especially when it comes to acquisitions by state-owned enterprises - and won't commit to releasing what conditions were attached to the takeovers.

"We have given clarity, the kind of clarity that private investors need. At the same time, we have reserved discretion and we need discretion to make sure when we're dealing with foreign governments that this government has the capacity to protect the bests interests of this country and its citizens," Prime Minister Stephen Harper said Monday in the House of Commons.

Pressed by the opposition on whether terms or conditions of the takeovers will be made public, the prime minister said the details will only be released "when it is proper to do that, and not, of course, in circumstances where it involves confidential commercial information."

But as the Tories came under attack Monday in the Commons over the investment guidelines, a leading business group in Harper's hometown of Calgary said greater clarity, transparency and reciprocity is needed when it comes to the Investment Canada Act.

The Calgary Chamber of Commerce said Monday the government's approval of the CNOOC and Petronas transactions is a great first step in demonstrating Canada is open for business and foreign investment. However, more must be done to improve and clarify the net benefit test in the Investment Canada Act so companies know what they're facing when it comes to foreign investment, the chamber says.

"We're in a position where we really need to strengthen that legislation, because going forward these deals are basically the first of a sign of things to come," said Ben Brunnen, director of policy and chief economist with the Calgary Chamber of Commerce.

The Alberta oilsands - the third-largest proven oil reserves in the world - represent about 56 per cent of total private sector oil investment opportunities worldwide, he said, so investors looking to Canada need a clearer set of rules.

"The demand for energy resources is going to be insatiable. It's important that we get our rules up to date and done right at this point in time because if we don't we're going to be scaring off some significant potential trade partners and investors moving forward to develop our energy resources," Brunnen added.

The federal government released an updated foreign investment framework on Friday that establishes new rules for state-owned enterprises (SOEs) and serves notice that foreign takeovers of Canadian oilsands companies won't be permitted going forward, except on "an exceptional basis only."

Ottawa announced the changes the same day it approved China National Offshore Oil Corporation's (CNOOC) $15.1-billion takeover of Calgary-based petroleum producer Nexen, and a $6-billion bid from Malaysian national energy company Petronas for natural gas producer Progress Energy Resources.

But the government didn't touch the "net benefit" test within the Investment Canada Act that applies to private foreign investment coming into Canada. The current legislation applies a broadly defined test to determine whether foreign investment meets the net benefit standard.

The Alberta government provided Ottawa a list of conditions it wanted attached to any federal approval of the CNOOC-Nexen transaction. Those conditions reportedly included guarantees that at least half of Nexen's board and management positions would be held by Canadians; for CNOOC to maintain current staffing levels for at least five years; and a commitment to maintain planned capital spending.

In a news release, CNOOC said it will "seek to retain" Nexen's current management team and employees, and invest "significant capital" on oil and gas resources in Canada. CNOOC has also promised to make Calgary its North and Central American headquarters and to list CNOOC shares on the Toronto Stock Exchange.

Interim Liberal leader Bob Rae said he's concerned about the lack of clarity in the CNOOC and Petronas approvals and how the government determined it was a net benefit to Canada.

"We're no better off than we were before in terms of understanding the reasons for the decision or the conditions which apply to the investment. So there's a complete lack of transparency," Rae said, calling for the terms, conditions and any guarantees from the approvals to be made public.

Alberta Intergovernmental Relations Minister Cal Dallas noted Monday he's comforted by CNOOC's commitments and said "the essence" of what Alberta suggested to the federal government has been met in Ottawa's approval of the transaction.

The provincial government is still seeking clarity, though, around what is considered a "net benefit" to Canada, including potential SOE joint ventures and "where that bar is set" on what's considered an "exceptional basis" when it comes to takeovers of oilsands companies.

"We're still looking for more information about what this means going forward," Dallas said. "We continue to suggest that we want to have more dialogue around . really understanding exactly where this is going."

David Collyer, president of the Canadian Association of Petroleum Producers, said Monday the government struck "a reasonable and pragmatic balance" with its decisions on foreign investment.

However, ARC Financial Corp., a Calgary-based private equity management firm, said putting restrictions on oilsands ownership "sends the wrong signal" to Canadians that they're the only ones "who hold an ace in a world where (oil) demand is moderating and supply is growing."

The federal NDP introduced a motion Monday in the House of Commons calling on the government to heed the advice of business groups - including the Calgary Chamber of Commerce - and introduce more clarity and transparency in how the government applies the net benefit test, as well as reciprocity from countries like China.

The official Opposition motion also called for the government to hold public consultations on the changes to investment rules.

"What we see is a very clear intent of this government to sell off Canada, regardless of the consequences," said NDP natural resources critic Peter Julian.