* TSX falls 1.5% to 19,810.69

* All ten major sectors end lower

* Canada posts surprise trade deficit

* Aritzia shares fall after brokerage downgrade

July 6 (Reuters) - Canada's main stock index on Thursday posted its biggest decline in nearly four months, in a broad-based sell-off, as the prospect of additional central bank interest rate hikes spooked investors.

The Toronto Stock Exchange's S&P/TSX composite index ended down 293.20 points, or 1.5%, to 19,810.69, its biggest decline since March 15.

Wall Street's main indexes

also ended lower after data showing a strong labor market boosted bond yields and fanned fears the Federal Reserve will be aggressive in raising U.S. interest rates.

"The TSX is trading cautiously today as market participants digest the surprisingly hot ADP jobs report," said Brandon Michael, senior investment analyst at ABC Funds.

"Focus is turning to higher for longer interest rates, which is weighing on the markets today."

All 10 major sectors ended lower. Rate-sensitive technology stocks lost 1.9%, energy fell nearly 2% and heavily weighted financials were down 1.6%.

The move lower came as data showed Canada recorded a surprise trade deficit in May.

Canada's employment report for June is set for release on Friday. The data could help guide expectations for next Wednesday's policy decision by the Bank of Canada.

The Canadian central bank will raise interest rates by a quarter-point for a second straight meeting to 5.00%, according to a majority of economists polled by Reuters.

Aritzia Inc was among the biggest decliners on Thursday. Its shares fell 5.8% after BofA Global Research downgraded the apparel and accessories retailer to "underperform" from "neutral". (Reporting by Fergal Smith in Toronto and Shashwat Chauhan and Siddarth S in Bengaluru; Editing by Shounak Dasgupta and Lisa Shumaker)