DAKAR/LONDON, Dec 5 (Reuters) - The United States' development lender announced plans on Friday to take a stake in a new partnership to market Congo's minerals which could give U.S. end users the right of first refusal on copper and cobalt supplies.

The U.S. is in a fierce contest with China to secure minerals crucial in the manufacturing of everything from iPhones to cars. Congo is home to about 72% of global cobalt reserves and accounts for over 74% of supply, much of it from artisanal mines. 

The investment plans emerged a day after U.S. President Donald Trump hosted the leaders of the Democratic Republic of Congo and Rwanda to sign a deal to end a drawn-out conflict in Congo's mineral-rich east and stabilise supply chains.

Trump called it a new era of harmony and cooperation that would bring peace and prosperity across the region, although neither country has implemented pledges underpinning the deal and renewed fighting erupted on Friday.

The peace agreement links security commitments to an economic framework opening up Congo's copper, cobalt, lithium and gold reserves to Western investors seeking critical minerals for EVs and clean energy.

REDEFINING HOW CONGO INTERACTS WITH METALS MARKETS

The U.S. International Development Finance Corporation said it has expressed interest in taking an equity stake in a new joint venture between Congo's state miner Gecamines and Swiss commodities group Mercuria to market copper and cobalt.

The partnership could expand to minerals including germanium and gallium - vital for semiconductors and solar panels - Gecamines and Mercuria said in a joint statement.

"This collaboration marks a pivotal step in Gecamines' journey to strengthen its role in the global metals market," said Guy Robert Lukama, Gecamines' chairman.

Under a potential deal with the International Development Finance Corporation, U.S. end-users would gain a right of first refusal on copper and cobalt supplies, the two companies said.   

The planned U.S. investment in the partnership would support commercialization of copper, cobalt and other critical minerals, giving U.S. and allied buyers access to responsibly sourced supplies essential for electric vehicles and clean energy, the lender said in a separate statement.

The partnership said it aims to improve transparency and competitiveness in the world's top cobalt producer, which recently introduced export quotas, launched traceable artisanal cobalt and on Friday announced new export conditions. 

Mercuria will provide logistics, financing and trading expertise under the deal and supply training in risk management and operations.

The venture also plans investments in export infrastructure to ease mineral bottlenecks, the statement said. 

Kostas Bintas, Mercuria's global head of metals and minerals, called the partnership "a redefinition of how Congo interacts with global metals markets".

DFC also signaled support for a separate project to rehabilitate the Dilolo-Sakania railway line in Congo, which could seek up to $1 billion in financing.

The line would connect to Angola's Lobito Atlantic Railway, creating a strategic corridor to move minerals and goods across Central and Southern Africa.

(Reporting by Anait Miridzhanian in Dakar and Marc Jones in London; Writing by Maxwell Akalaare Adombila; Editing by Joe Bavier and Philippa Fletcher)

By Anait Miridzhanian and Marc Jones