Shunichi Miyanaga, the president and chief executive of Mitsubishi Heavy Industries, said his company's bid is progressing smoothly and expected the government would announce the successful firm sometime this year.

Mr Miyanaga is in Australia and has visited the ministers from defence, trade and industry ministers or their representatives, as well has shipyards in Adelaide and Perth and academics for the country's biggest universities.

He dismissed a report published in the Financial Times this week that the Australian government had in the past two months been laying increasing pressure on Japan to tighten the commercial terms of the bid and outline a detailed budget so it can gauge which company is leading the submarine project.

When asked if that report was true, Mr Miyanaga said: "I don't think so".

"As the leading company of this project… I have come here and I think the bidding process … is [making] very smooth progress. We have been exchanging the questions and answers so I don't have any such kind of concerns and problems."

Mr Miyanaga's comments came after he told reporters in Adelaide this week that Mitsubishi could build Australia's new submarine fleet in Australia if it won the contract, which could be worth up to $50 billion.

He didn't rule out investing in the government-owned Australian Submarine Corporation (ASC) to improve the chances of Mitsubishi's bid.

"I have expressed our willingness to do the business in Australia. In many countries we have been operating very smoothly and well in the form of joint ventures, sometimes in the form of 100 per cent investment, sometimes acquisitions, sometimes new investment.

"But I would like to discuss further [the prospect of investing in ASC]. We have been very successful in this kind of gigantic project to form such collaboration schemes, sometimes in a joint venture in the early stages, which can be taken over, step by step, by the customer country's companies."

Mitsubishi has been operating in Australia since the 1950s and generates revenue of about $35 billion a year. Its operations include rocket launches and the manufacture of jets, gas turbines, high speed rail and forklifts as well as submarines.

It is It is competing against French bidder DCNS and German bidder TKMS, part of the ThyssenKrupp multinational group for the submarine contract.

All three of the competing bidders lodged their proposals late in 2015 under the timetable set by the federal government, with a decision expected by mid-2016.

Mr Miyanga said he was confident Australia's shipbuilding industry could build the country's new fleet of submarines, although he didn't specify a percentage of how much the build would be local if Mitsubishi won the contract.

"My visit this time is very assuring visit. I have found very strong confidence in expertise in shipbuilding. We'd like to work together with the Australian people and send our people [here] and have some people come to Japan.

"We'd like to make as possible as we can in Australia and I have found the Australian industries are very fortified and have very high skills and expertise."

One aspect of the project he was looking forward to, if Mitsubishi was successful, was the development of a design centre which would draw on the expertise of Australian industry leaders and university researchers.

"It would both in Japan and Australia. At the very beginning… the Japanese design centre would be a little bigger. Then, step by step, the Japanese design centre would become smaller and the Australian design centre would become larger.

"We'd establish a very specific design centre but we'll add a lot of related engineering collaboration organisations. For example I have met several professors in Perth and Adelaide and here, this morning, I was at the Monash University to discuss the further collaboration possibilities.

"I am excited to explore information technologies and other technologies. We'd like to connect such collaboration centres in Australia with this design centre for submarines."