China's US$37 billion bet on Canadian energy producers, from Sunshine Oilsands to Penn West Petroleum, is producing disappointing results amid sinking resource prices and operational breakdowns.

Penn West and Sunshine, partly owned by China Investment Corp, the nation's sovereign wealth fund, have tumbled 17 per cent and 48 per cent respectively this year. Syncrude Canada, whose owners include CNOOC and China Petrochemical Corp, cut its production target three times; while declining natural gas prices have triggered a review of Sinopec Daylight Energy's assets.

"The talk around the table is that the Chinese were not informed investors," said Sam La Bell, a Toronto-based analyst at Veritas Investment Research. "They had a long-term view that oil was going up and they had a mandate to go buy oil assets. They weren't necessarily being selective."

Chinese investments in Canada's energy sector have cooled this year to less than US$1 billion, after a record US$19.3 billion in 2012, including CNOOC's US$15.1 billion acquisition of Nexen.

China has invested about US$37 billion in the industry since the beginning of 2008.

The slowdown in acquisitions and lower returns come after Prime Minister Stephen Harper last year imposed limits on oil-sands purchases by state-owned enterprises.

Falling fossil fuel prices, delays in building pipelines for exporting oil, and the time and money to understand how to operate in the world's third-largest oil reserves have led to a difficult year for Chinese investors, said Goldy Hyder, president of Hill+Knowlton Strategies Canada which advised CNOOC during its purchase of Nexen.

"There's angst around Canada these days and more than a bit of 'buyer beware'. Next year we may start to see some cracks appearing, especially in the joint ventures over differences of opinion," he said.

Felix Chee is stepping down as head of CIC's Toronto office, according to two people familiar with the fund's plans.

CIC opened its first overseas office in Toronto two years ago with a mandate to expand into Canada's natural resource sector. The fund may expand its North American presence with a United States office, while keeping its Toronto location open, said one of the people, who asked not to be named.

Chinese investors have been "buying all this stuff and not making returns," said Wenran Jiang, a University of Alberta professor and adviser to the Alberta government and industry. "We should be very grateful to the Chinese who virtually put all their money into subsidising our losing energy market."

Among CIC's first major investments in Canada was a US$1.5 billion stake in Teck Resources, in July 2009.

A year after that purchase, CIC and Penn West announced they would jointly develop an oil-sands project in Alberta through a partnership in which CIC agreed to invest C$817 million (HK$5.92 billion) for a 45 per cent stake.

That joint venture is now among as much as C$2 billion in assets Penn West plans to sell as Dave Roberts, its chief executive since June, tries to engineer a turnaround of the Calgary-based company. CIC bought a 5 per cent stake in Penn West as part of the deal.

"The investment in Penn West was probably a bad idea," said La Bell. Penn West, which underwent a board and management shake-up to address rising costs and high debt, has lost 56 per cent since the May 13, 2010 agreement, compared with a 3.8 per cent rise among Canadian energy companies.