* Dollar rebounds vs euro and yen as stocks gain globally

* China markets closed, ECB policy meeting awaited for cues

* Loonie sags before Canada trade data

* Aussie near 6-1/2 year low after weak retail sales data (Adds details, quotes)

By Shinichi Saoshiro

TOKYO, Sept 3 (Reuters) - The dollar climbed against the euro and yen on Thursday as global investors tentatively stepped back into equities, tempering demand for the single currency and the Japanese unit.

The dollar was up 0.2 percent at 120.570 yen, having rebounded sharply from a low of 119.255 overnight. The euro dipped to $1.1216, adding to an overnight loss of 0.8 percent.

The ebb and flow in global risk appetite, heavily influenced by Chinese economic data and its volatile stock markets, have recently influenced the greenback's day-to-day direction.

Global stock indexes extended gains Thursday after receiving a midweek lift from reports of brokerage measures in China, whose financial markets are closed Thursday and Friday for holidays, to invigorate the country's battered markets.

Tokyo's Nikkei climbed 1.4 percent.

China's slowing economy and worries about global growth had prompted investors to reduce bets in the yen and the euro, both of which have been popular for funding trades involving the sale of low-yielding currencies to buy higher-yielding, but riskier, assets.

Stock market gains have tended to slow unwinding of such "carry trades", exposing the dollar to higher volatility.

Data released from the Commodity Futures Trading Commission last week showed International Monetary Market (IMM) speculators' net short yen contracts falling to their lowest since mid-May and net euro shorts shrinking to their smallest in more than a year.

"IMM data suggests that the unwinding of carry trades has passed its peak. A bulk of the yen and euro shorts may have been covered, but it remains to be seen if investors are bold enough to now go long on these currencies," said Masashi Murata, senior currency strategist at Brown Brothers Harriman in Tokyo.

"Currently, a strong case to go long on the yen and euro against the dollar does not exist, with the possibility of the Federal Reserve hiking rates in September still alive. A clear trend has not formed and that is part of the reason the dollar moves along daily with each turn in equities," he said.

With Chinese markets closed, the focus will be on the European Central Bank policy meeting later in the session and on what its officials make of recent turmoil in financial markets.

"We expect a dovish message in the press conference and believe further easing is likely before year end. Such a message should support sentiment, which so far has been a drag on risky assets," strategists at Barclays wrote.