Australia will reap fewer benefits from the planned Trans-Pacific Partnership trade deal than most of the other members, according to the first comprehensive research on the economic impact of the deal since it was agreed in   October. 
The findings on the main beneficiaries come as the prospects of the deal being implemented appear to have been improved significantly in the new year, with key US business groups endorsing it after earlier equivocation.
New Zealand is also reported to be planning to host a signing ceremony early next month to maintain the momentum towards full implementation, after opposition in the US Congress threatened to delay ratification in the US until after the   November presidential election.
President Barack Obama is expected to push for US ratification before he leaves office in his final State of the Union address on Tuesday, drawing on the new official statements of support from three peak business groups.
But research by the World Bank shows that Australia is likely to experience a gross domestic product increase of less than two percentage points by 2030 as a result of the increased business flowing from the trade deal among 12 countries.
This compares with GDP increases of about 10 per cent for Vietnam and 8 per cent for Malaysia. They benefit from getting new access to larger markets in the US and Japan, which Australia already has.
Australia will also have one of the smallest overall increases in exports by 2030 of about 5 per cent, compared with about 30 per cent for Vietnam and 10 per cent for the US.
The US-led TPP was agreed between trade ministers from the 12 members in   October after seven years of negotiations, but still needs to be ratified by the parliaments of most member countries. It covers 25 per cent of world trade and 36 per cent of the global economy.
While the World Bank study released last week underlined how Australia's already open trade regime makes it one of the lesser beneficiaries, it welcomed the agreement as a potentially important offset to declining world trade growth.
"As a new-generation, deep and comprehensive trade agreement, TPP addresses a wide range of complex trade policy issues that go beyond the scope of traditional trade agreements.
"The agreement will reduce tariffs and restrictiveness of non-tariff measures as well as harmonise a range of regulations to encourage the integration of supply chains and cross-border investment."
The World Bank study's findings on the beneficiaries from the final agreement are broadly in line with earlier academic forecasts about the deal.
However, the Australian government argues that the nation may reap other longer-term benefits by being on the inside of what might become the main framework for business rule-making across the Asia Pacific region.
The World Bank lends weight to this argument by saying: "Against the background of slowing trade growth,rising non-tariff impediments to trade, and insufficient progress in global negotiations, the TPP represents an important milestone.
"The TPP stands out among FTAs (free trade agreements) for its size, diversity and rule-making."
It says: "Much will depend on whether the TPP is quickly adopted and effectively implemented."