LONDON (Reuters) - Indian conglomerate JSW Steel and global trading firm Duferco are in advanced talks on a five-year cash-for-steel prepayment deal, four sources familiar with the matter said, in a rare move for the industry.

FILE PHOTO - The logo of JSW is seen on the company's headquarters in Mumbai, India, February 11, 2016. REUTERS/Danish Siddiqui

JSW, India’s biggest steelmaker, and Duferco had a prepayment deal in 2006 for $150 million in upfront cash that would be repaid over seven years with steel cargoes, but the scale of the proposed new deal is much larger.

Two sources said the deal, expected to be signed this quarter, would be worth about $600 million. Switzerland-based Duferco, backed by banks, would provide the cash to be repaid with physical steel.

Duferco, one of the world’s largest steel trading firms, declined to comment. JSW did not confirm the value of the deal, but said it has a longstanding relationship with Duferco that involves financing arrangements.

One of the sources said JSW was looking for alternate sources of funding while, for Duferco, the deal would lock in future sales of steel with its clients.

Jeff Kabel, chairman of the International Steel Trade Association (ISTA), said the deal would represent “a great move forward” for an industry that has seen few such arrangements to date.

Steel derivatives, which allow buyers and sellers to lock in future prices, are still in their infancy, making trade houses wary of pre-paying for large tonnages and risk prices moving against them in the future.

Such deals are frequent in commodities such as oil, with liquid derivatives markets that allow for hedging future sales.

A $600 million dollar deal would equate to about 1 million tonnes of steel supply.

“Its rather innovative. The only thing steel companies usually do is pre-export finance and not that big a number,” said Kabel, referring to financing options that do not involve repayments in physical cargoes.

In 2013, as banks increasingly withdrew from Europe’s steel sector, Duferco moved to offer its clients trade financing, though these deals typically involved it acting as a bank, not taking delivery of steel.

JSW plans to expand steelmaking capacity by 2030 to between 44 million tonnes and 45 million tonnes from 19 million tonnes currently.

In 2017 it earmarked $1 billion for acquisitions and expansion but has had to proceed more cautiously this year as steel prices have fallen to their lowest in nearly a year and there are growing concerns the upcycle might reverse.

Duferco, controlled by state-owned Hebei Iron and Steel Group (Hesteel), China’s largest steelmaker, has activities in more than 120 countries and sales of about 20 million tonnes of steel and raw materials a year.