The non-executive position is the West Australian's first job in the private sector since she bowed out of politics after more than 20 years at the election.

The opposition's foreign affairs spokeswoman Penny Wong said Ms Bishop had been appointed because of her global network of contacts.

"Not only doesn't it pass the pub test, it looks on the face of it like another breach of the ministerial standards," Senator Wong told ABC News on Tuesday.

She said Palladium had profited more than $500 million from decisions made when Ms Bishop was foreign minister.

Labor has also raised questions about former defence minister Christopher Pyne's role with major consultancy company EY.

The opposition believes both ex-cabinet ministers may have breached the ministerial code of conduct because they are using information not available to the general public.

"It isn't sufficient for either Christopher Pyne or Ms Bishop to say, 'I think I am complying' and that to be the end of the matter," Senator Wong said.

"This is a test of the prime minister's integrity."

Earlier, Ms Bishop said joining Palladium would continue her long-standing interest in economic development in the Pacific and beyond.

"Palladium has a focus on private sector engagement to deliver effective, sustainable development and even invests its own money into projects," she said in a statement.

Palladium chief executive Kim Bredhauer said Ms Bishop has plenty in common with the company.

"We are both committed to inclusive growth, resulting in sustainable solutions around the world."

Ms Bishop confirmed last month she is also becoming chair of the Telethon Kids Institute, a Perth-based research hub.

Australian Associated Press