Hockey worried about ADM's character

Concerns about US agribusiness Archer Daniels Midland's corporate character were partly behind Joe Hockey's decision to block its proposed $3.4 billion takeover of GrainCorp.

The treasurer was slammed for rejecting the foreign investment deal last year as the Abbott government was touting Australia as open for business.

But Mr Hockey told a Sydney audience on Wednesday he considered a range of issues before deciding the takeover was contrary to the national interest.

One of those was clearly corporate character.

"I had reason to believe that ADM at that time were not particularly good character," Mr Hockey said during a question and answer session hosted by the Spectator Magazine.

That was "obviously confirmed" by ADM's $50 million fine in the US for "corrupt activity" in another jurisdiction, Mr Hockey said.

The Foreign Investment Review Board was split in its advice to him prior to his decision.

Farm groups and the Nationals had campaigned heavily against the deal, which would have given ADM control of 85 per cent of Australia's east coast grain ports

The treasurer says he has approved more than 500 investments that he believes are good for Australia.