Australia’s share market alternated between gains and losses early and was little changed after two hours as investors were reminded of the coronavirus threat in the US.

The S&P/ASX200 benchmark index was down 3.1 points, or 0.04 per cent, to 6446.6 at 1200 AEDT on Thursday.

The All Ordinaries dropped 3.2 points, or 0.04 per cent, to 6647.9.

Major sectors were trading lower. Financials was down 0.79 per cent, materials was down 0.68 per cent and energy dropped 1.07 per cent.

Telecommunications was doing best, up 2.99 per cent, after Telstra outlined a restructure.

US markets closed with mixed results after some states across the US tightened coronavirus restrictions.

The news appeared to end trading momentum from Pfizer’s announcement on Tuesday that its coronavirus vaccine, being developed, was 90 per cent effective.

In Australia, Telstra will undergo its biggest restructure in 24 years, splitting its business into three separate legal entities.

The new divisions under the group umbrella are InfraCo Fixed, holding its infrastructure assets, InfraCo Towers, covering its mobile towers and ServeCo which will look after customers and product development.

Shares were up 4.84 per cent to $3.13.

Nine Entertainment says the advertising market has improved significantly and it expects 15 per cent revenue growth from metropolitan areas in its second quarter.

The media company told its annual general meeting on Thursday that its share of the ad market had been helped during this period by major events including the NRL finals and State of Origin.

This meant metropolitan ad revenue for the half-year would be little changed on the previous six months.

Shares were up 4.02 per cent to $2.45.

Among the big banks, ANZ lost 0.09 per cent to $20.81, the Commonwealth slipped 0.89 per cent to $73.73, NAB shed 1.64 per cent to $21.46 and Westpac dipped by 1.17 per cent to $18.51.

In mining, BHP lost 0.59 per cent to $36.63, Rio Tinto edged lower by 0.02 per cent to $97.14 and Fortescue fell 3.29 per cent to $16.72.

Earlier in the US, investors switched back to technology stocks and away from economically sensitive sectors as they weighed COVID-19 vaccine progress against a virus surge and likely timing for a economic rebound.

The Dow Jones Industrial Average fell 23.29 points, or 0.08 per cent, to 29,397.63, the S&P 500 gained 27.13 points, or 0.77 per cent, to 3,572.66 and the Nasdaq Composite added 232.58 points, or 2.01 per cent, to 11,786.43.

The Aussie dollar was buying 72.83 US cents at 1200 AEDT, lower from 73.09 US cents at Wednesday’s close.