* Higher oil prices on output slump benefit energy shares

* Copper prices continue to strengthen on tight supply

* Tech stocks track Wall Street peers lower

Feb 23 (Reuters) - Australian shares closed nearly 1% firmer on Tuesday, as strength in commodities boosted market expectations of an improved growth outlook and lifted miners and energy stocks.

The S&P/ASX 200 index was up 0.9% at 6,839.2 by the close of trade.

Participants also kept an eye out for possible changes to the U.S. Federal Reserve's outlook from Chairman Jerome Powell in his testimonial before the Senate Banking Committee later in the day.

Commodity prices strengthened as oil prices rose on a tight global supply outlook after U.S. production was hammered by frigid weather and an approaching meeting of top crude producers is expected to keep output largely in check.

Australian energy stocks rose 4.9% on firmer oil prices.

Oil and gas explorers Woodside Petroleum and Santos Ltd advanced 5.7% and 5.9%, respectively.

Gold stocks jumped 2.8%, with spot gold hitting a one-week high as inflation worries boosted the bullion's appeal as a hedge.

Miners climbed 2% on the back of a continued rise in copper prices, helped by tight supply and expectations of strong demand.

Copper-exposed global miners BHP Group and Rio Tinto gained 3.1% and 1.8%, respectively.

Top independent gold miner Newcrest Mining jumped 4.4%, while peer Bellevue Gold rose 5.1%. Financials also rose, with the so-called "Big Four" banks gaining in the range of 1.1% to 1.9%.

Tech stocks tracked Wall Street peers lower to drop 4.1%, with buy-now-pay-later co Afterpay Ltd falling 7.2%, while accounting software maker Xero Ltd lost 2.7%.

SEEK Ltd closed 7.1% lower after the job portal operator said it was in talks to cut its stake in Chinese unit Zhaopin for A$2.2 billlion ($1.74 billion).

In New Zealand, the benchmark S&P/NZX 50 index fell 0.3%, pulled down by utility and healthcare stocks.

($1 = 1.2628 Australian dollars)

(Reporting by Soumyajit Saha in Bengaluru, Editing by Sherry Jacob-Phillips)