Aug 16 (Reuters) - Canada's main stock index slipped on Monday after Prime Minister Justin Trudeau called an early election as widely expected, while energy stocks tracked a decline in oil prices on the back of dour economic data from China.

At 9:38 a.m. ET (1338 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 66.55 points, or 0.32%, at 20,451.52.

Trudeau, in calling for the snap election on Sunday, said he needed a new mandate to ensure voters approved of his Liberal government's plan to recover from the pandemic.

The Canadian dollar was down 0.3% at 1.25615 to the greenback, with analysts saying the weakness was partly due to data showing a surprisingly sharp slowdown in China, which sparked fears of a wobbly global recovery from the COVID-19 lows.

"Those large trading partners (with Canada), they're starting to slow," said Bryden Teich, a portfolio manager at Avenue Investment Management.

"Canada is so tied to the commodities cycle that if that sort of stalls out, the more cyclical parts of the markets in Canada can get hurt."

The heavyweight energy index sank 2.2% on Monday, trimming some of its 30% gains made so far this year.

HIGHLIGHTS

* The financials sector was another big decliner in morning trading, down 0.6% after hitting a record high on Friday.

* On the TSX, 84 issues were higher, while 139 issues declined for a 1.65-to-1 ratio to the downside, with 23.16 million shares traded.

* A 5.2% gain propelled mortgage lender Home Capital Group Inc to the top of the TSX after a clutch of brokerages including National Bank of Canada raised their price targets on its stock.

* Weed producer OrganiGram Holdings Inc, on the other hand, tumbled 6.4% to the bottom of the TSX.

* The most heavily traded shares by volume were Manulife Financial Corp, Nevada Copper and Enbridge Inc .

* The TSX posted 11 new 52-week highs and no new low.

* Across all Canadian issues there were 49 new 52-week highs and seven new lows, with total volume of 42.70 million shares. (Reporting by Sagarika Jaisinghani, Sruthi Shankar and Amal S in Bengaluru; Editing by Shounak Dasgupta and Sriraj Kalluvila)