Dec 23 (Reuters) - Australian shares rose on Wednesday on the back of gains in financial and tech stocks after three straight sessions of losses due to fears over a fast-spreading new COVID-19 strain and fresh restrictions at home.

The S&P/ASX 200 index rose 0.8% to 6,654.20 by 0039 GMT.

The benchmark index dropped more than 2% over the past three sessions as the detection in Britain of the new coronavirus variant prompted many countries to shut their borders with the nation, raising fears of a slower global economic recovery.

"Europe and the U.S. are high risk areas and money is leaving them and moving to other regions like New Zealand and Australia, where market risk is nearly the same but pandemic risk is much lower," said Mathan Somasundaram, chief executive at Deep Data Analytics.

"The likelihood is that we see the early optimism fading through the day."

Australia's most populous state on Wednesday "modestly" relaxed some restrictions just for the Christmas period following a second straight day of low case numbers, although parts of Sydney's northern seaside suburbs remain in a lockdown.

Leading the gains, Australian tech stocks rose as much as 2.2%. Buy-now-pay-later firm Afterpay and Wisetech Global each climbed over 3%.

The Healthcare sector rose 1.1%, with CSL Ltd advancing 1.3% and Mesoblast firming nearly 10%.

Shares of Orthocel jumped 13.4% after the biotech firm said it received Australian market approval to supply its CelGro collagen medical device in dental bone and tissue regeneration procedures.

The heavyweight financial sub-index strengthened 1%, with all the "Big Four" banks posting gains.

Bucking the trend, miners fell 0.9%.

BHP Group shed 0.7%, while Rio Tinto was marginally lower.

New Zealand's benchmark S&P/NZX 50 index climbed 0.8% at 12,949.68.

Both Meridian Energy and a2 Milk gained over 4%.

(Reporting by Nikhil Subba in Bengaluru; Editing by Aditya Soni)