* J&J targets COVID-19 late-stage trial results by January

* Aussie tech stocks hit record high

* Infratil soars after rejecting $3.78 bln buyout offer

Dec 9 (Reuters) - Australian shares extended their rally to a seventh session on Wednesday, tracking gains in the Wall Street after encouraging vaccine news boosted U.S. indexes to a record high, with domestic healthcare and technology stocks leading the charge.

Major averages on Wall Street touched record levels on Tuesday after Johnson & Johnson became the latest in a slew of companies to report positive results for its COVID-19 vaccine candidate.

The S&P/ASX 200 index gained up to 0.8% and touched 6742.5 points, its highest level since Feb. 26.

Adding to the positive sentiment, a measure of Australian consumer sentiment climbed for the fourth straight month in December to a 10-year high, amid gradual border re-openings between states.

Except for energy stocks, all major sub-indexes were trading in positive territory.

Tracking peers in the United States, local healthcare stocks led gains, jumping as much as 2.4%. Shares of Healius rose the most, hitting their highest in over a month.

Tech stocks hit a record high, with gains in Xero and Afterpay among top boosts to the sub-index.

An overnight dip in oil prices on surging infections and lockdown worries dragged the energy index 0.6% lower. Origin Energy and Woodside Petroleum lost up to 1.5% and 1.7%, respectively.

Nickel and gold miner IGO Ltd went into trading halt before announcing that it would take a 25% stake in Greenbushes lithium mine from China's Tianqi for $1.4 billion.

Commonwealth Bank of Australia said it would now fetch more from the sale of its stake in a Chinese life insurer to Japan's Mitsui Sumitomo Insurance Co after China's banking regulator green-lit the deal.

CBA's shares rose 1.6% to their highest in two weeks.

In New Zealand, the benchmark climbed up to 1.5% and was set for its best day in a month.

Infratil was the top percentage gainer after rejecting a $3.78 billion buyout offer from AustralianSuper, calling out the bid for undervaluing its renewable energy and digital infrastructure platforms. (Reporting by Arundhati Dutta in Bengaluru, Editing by Sherry Jacob-Phillips)