UPDATE 1-Shopify posts bigger quarterly loss on higher spending

(Adds details, share movement)

Oct 29 (Reuters) - Canada's Shopify Inc posted a bigger quarterly net loss on Tuesday as it spent more to add sellers to its e-commerce platform and expand fulfillment centres across the United States, sending shares down 8.6% before the bell.

The company had said in June it planned to spend over $1 billion for more fulfillment centres, as it faces stiff competition from Amazon.com Inc and EBay Inc.

Total operating expenses in the third quarter rose to $252.4 million from $181.1 million a year earlier.

The company's net loss tripled to $72.8 million, or 64 cents per share, in the quarter ended Sept. 30, from a year earlier.

The Ottawa-based company reported a total revenue of $390.6 million, up 45% year-over-year.

The company expects revenue between $472 million and $482 million in the fourth quarter, above analysts' expectations of $470.6 million.

(Reporting by Ambhini Aishwarya in Bengaluru; Editing by Shinjini Ganguli, Arun Koyyur)