SYDNEY (AFP) - The landmark Sydney Harbour Bridge is to undergo its biggest makeover since 1932, with a new coat of paint that will take two years to complete, the New South Wales state government said on Thursday.

The bridge, which links the northern and central parts of the city and is one of the world's most recognisable symbols, will be sanded back to bare steel and repainted for the first time in its 81-year history.

"This grande dame of Sydney Harbour is getting a makeover with a high performance fade-resistant paint to help her endure the punishing conditions," state Roads Minister Duncan Gay said in a statement.

Huge sections of the bridge have suffered from rust and corrosion in recent decades with some 485,000 square metres of steelwork - the equivalent of 60 football fields - needing to be painted.

"The new paint, still in that famous shade that we call 'Harbour Bridge grey', is expected to last 30 years and won't darken or change over time," Mr Gay said.

"We need the bridge in top condition, she's always in the limelight with thousands of international and local visitors flocking to visit and enjoy events like Vivid Sydney and New Years Eve fireworks."

Fifty painters will carry out the work that is expected to cost A$20 million (S$24.4 million).