Leaders from the BRICS emerging nations are expected to launch a joint development bank to rival western-dominated institutions at a summit beginning Tuesday.

Leaders from the BRICS emerging nations are expected to launch a joint development bank to rival western-dominated institutions at a summit beginning Tuesday.

The grouping of Brazil, Russia, India, China and hosts South Africa will meet in Durban to set up an infrastructure-focused lender that would challenge seven decades of dominance by the World Bank.

Xi Jinping, who has underscored the growing importance of the group by making Durban his first summit as China's president, expressed hopes for "positive headway" in establishing the bank.

If the leaders succeed it would be the first time since the inaugural BRICS summit four years ago that the group matches rhetorical demands for a more equitable global order with concrete steps.

Together the BRICS account for 25 percent of global GDP and 40 percent of the world's population.

Details of how the BRICS bank would work have yet to be finalized, but diplomats say it could start with $10 billion seed money from each country.

That would be dramatically scaled back from initial, more ambitious proposals for a $50 billion buy in from each country.

The exact role of the bank is also up for debate.

Western officials had been wary for the idea of a BRICS bank, but have since tempered their view.

The World Bank chief economist and former Indian civil servant Kaushik Basu said there is plenty the bank could do, but warned setting it up would be a "humongous task".

Aside from the development bank, the group will also try to establish a foreign exchange reserve pool worth as much as $240 billion to be drawn on in financial crises.

BRICS leaders will also establish business and think tank councils and discuss a ranking system for non-western universities.