National Australia Bank Ltd (NAB), Australia's largest lender, said on Monday it had agreed to buy a 20 percent stake in a Chinese property investment trust, its first acquisition in China.

NAB did not disclose the price it paid for the stake in Union Trust and Investment Ltd (UTI), but one source estimated it to be about 50 million Australian dollars (US$41.3 million), valuing the Chinese company at around 250 million Australian dollars.

NAB said buying a stake in UTI, which manages property trusts, fitted in with its strategy of expanding existing capabilities into new areas.

Prior to the UTI stake buy, NAB had a representative office in Beijing but overall the bank has stayed away from buying strategic stakes in Asian banks.

Australia and New Zealand Banking Group Ltd, Australia's third-biggest bank, is the most aggressive lender in Australia to pursue Asian expansion, while the Commonwealth Bank of Australia Ltd too has investments in Asian banks.

NAB's 20 percent stake is the maximum it could have bought under the China's current regulations.