Several economic projects were blocked or delayed in the previous three years, often on the word of the Green Party's Eugenie Sage, in her roles of Minister of Conservation and Land Information.
In one case, she blocked an expansion project of the Oceania Gold Mine at Waihi, though rival Ministers later overturned this.
In another case, she blocked Malaysian-owned Ernslaw One from converting 630 hectares of sheep and beef land into forestry.
Another ruling put limits on expansion plans of Oji Fibre Solutions, which runs mills at Kinleith and Kawerau.
Many of these decisions were made in her capacity as Minister for Land Information, which governs the Overseas Investment Office.
That role has been taken over by O'Connor, who is also Minister for Trade and Export Growth, Biosecurity, and Rural Communities.
He was asked what difference his appointment as Minister for Land Information would make to these sort of decisions.
"I am a different person and I represent the Labour Party and we have always worked positively with people in the High Country and in all areas where land has some influence."
O'Connor said he had strong bottom lines in terms of environmental impacts from ventures such as mining and farming.
"But if people can mitigate any of those impacts, then we should get on - we need economic development, we need jobs, we need export income," he said.
"I have always tried to be pragmatic, but I am also ambitious for our country, for the environment and for people who commit money to our businesses to get a better return."
- RNZ