Alberta’s minister of international relations says Ottawa needs to clarify its rules on foreign investment in Canada.

Cal Dallas told an audience at the Global Petroleum Show in Calgary on Wednesday that he tries to sell the province to foreign delegates, but the federal government’s regulations sometimes get in the way.

"There is some confusion regarding the new federal rules over foreign investment,” he said.

"We're doing our best to encourage investment in our province, from both private and state-owned enterprises."

The federal government reviews foreign acquisitions of Canadian businesses over a certain value. This year, the threshold for review is $354 million.

In late 2012 Ottawa put new limits on investment by state-owned firms in the oil patch.  

Dallas said foreign investment is essential for Alberta’s energy sector to continue to grow, so he's working with Ottawa to make the review process more transparent.

The minister suggested companies interested in attracting foreign dollars could try avoiding a review by aiming for smaller buy-ins.

"There are many opportunities that fall below the thresholds or do not require a controlling interest,” he said.