Joe Oliver's move to the finance portfolio led to minor changes to the federal cabinet Wednesday, with the prime minister naming Greg Rickford as the new natural resources minister.

Later in the day, Oliver told the Canadian Press that the Harper government will keep its campaign promise on income splitting. But he said he wants time to study the issue before announcing details of how it might work.

Oliver is leaving the natural resources portfolio to take over the finance ministry from Jim Flaherty. Flaherty resigned from cabinet yesterday, indicating he will eventually take a job in the private sector. 

Flaherty had questioned whether income splitting was a good idea, causing a rift in the Conservative caucus.

But late last month, Prime Minister Stephen Harper reaffirmed his support for the policy, saying it would be a welcome break for families.

Oliver had suggested he would speak to reporters after his swearing-in, but instead said only a few words as he climbed into a waiting car.

Oliver has a law degree from McGill and a Harvard MBA. He worked in the investment banking industry and served as executive director of the Ontario Securities Commission.

One of Flaherty's long-running fights was to establish a single securities regulator in Canada instead of the individual regulators in each province. Last fall, British Columbia and Ontario both agreed to sign onto a voluntary "co-operative capital markets regulatory system."

Rickford moves to natural resources

Flaherty will remain an MP for the time being, his spokesman told CBC News.

CBC News asked for interviews with Oliver, Rickford and Holder, but they all declined and issued written statements instead.

Rickford, the MP for Kenora, Ont., moved to natural resources from minister of state for science and technology. He has also been parliamentary secretary to the minister of aboriginal affairs.

Rickford was first elected in 2008. Appointing an MP whose riding is affected by the massive Ring of Fire mining project could indicate a shift in emphasis from oil and gas to mining in the natural resources portfolio. He also has experience working with aboriginal groups, something that will come in handy on a range of extractive projects.

Greg Rickford and daughter at Rideau Hall

Greg Rickford leaves Rideau Hall with his daughter, Abigail Mae, after he was sworn in as Minister of Natural Resources, Wednesday, March 19, 2014 in Ottawa. (Adrian Wyld/Canadian Press)

Oliver often clashed with environmental groups and others who opposed expanded oil and gas development, famously calling them radicals.

London West MP Ed Holder is replacing Rickford in the science and technology file.

Holder was first elected in 2008 and most recently sat on the industry and international trade committees.

Prime Minister Stephen Harper was at Rideau Hall for the swearing-in, for which no press release was issued. Harper was hidden from reporters and photographers as he entered and exited Rideau Hall.

with files from the Canadian Press