The sharemarket has opened almost 1.5 per cent weaker as former Italian prime minister Silvio Berlusconi's strong electoral showing sparked fears of eurozone instability.

At 10.26am AEDT the benchmark S&P/ASX200 index was down 75.1 points, or 1.49 per cent, at 4,980.7 points, while the broader All Ordinaries index was down 73.3 points, or 1.44 per cent, to 4,999.4 points.

On the ASX 24, the March share price index futures contract was down 74 points at 4,968 points, with 10,887 contracts traded.

The local market followed Wall Street lower, after Mr Berlusconi's centre-right coalition appeared to be ahead in the Senate race, but only slightly behind in the lower house.

CMC Markets chief market analyst Ric Spooner said the possibility of a political impasse in Italy for an incoming government was creating uncertainty amongst investors.