Mercuria Energy Group has placed another big bet on copper production in the Democratic Republic of Congo, sealing a deal to buy metal from units of Shanghai Jayson New Energy Materials Group.

The agreement is the latest example of how trading houses are paying large sums in advance to secure access to copper as prices soar, while price disparities in different markets offer additional opportunities for profit.

Mercuria will pay Jayson subsidiaries Hongkong Excellen Mining Investment Co and Singapore Excellen up to $250-million for three years of supply from operations in Congo, including the newly started Kinga Kila project, according to people familiar with the matter, who asked not to be named discussing a non-public deal.

A spokesperson for Mercuria declined to comment. Jayson and representatives at Hongkong Excellen and Singapore Excellen didn’t immediately respond to requests for comments.

An investment vehicle belonging to Robin Zeng, the billionaire chairperson of battery giant Contemporary Amperex Technology Co (CATL), owns nearly 30% of Hongkong Excellen, which holds the Congolese copper ventures. Jayson, whose main business includes manufacturing precursor materials for lithium-ion batteries, controls the rest of the company.

CATL didn’t immediately respond to a request for comments.

Traders have been piling into prepayment deals in Congo, which has emerged as the growth engine for global copper supply and cemented its status as the second-biggest producer of the metal after Chile. Trafigura Group paid Ivanhoe Mines $200-million in advance for copper anodes from the Kamoa-Kakula complex, while Mercuria paid $100-million to guarantee access to three years of copper output from Eurasian Resources Group.

The syndication to finance the majority of Mercuria’s advance to Jayson is expected to be supported by Rabobank, among other lenders, the people said, underscoring the appetite of commodity financiers to back these kinds of arrangements.

Rabobank declined to comment.

In Congo, Mercuria has also set up a joint venture to help the state mining firm market tons of copper and cobalt it gets from equity interests in several projects in the country.

Jayson’s trio of projects in Congo produced about 56 000 t of copper in the first half of the year, according to government data. The latest began exporting metal in May.

CATL holds a 25% interest in China’s CMOC Group, which leads copper production in Congo with two giant operations. The battery maker also owns an additional stake of the same size in CMOC’s Kisanfu mine, which is the world’s top source of battery material cobalt.

The two metals are often found together in Congo.