The Chinese government selected a state-owned company to negotiate a concession to operate a line connecting Zambia’s copper-mining heartland with the Tanzanian port of Dar es Salaam, which may require as much as $1 billion in investment.

A China Railway Construction Corp. unit has been asked to submit its proposal by the end of October, the Tanzania-Zambia Railway Authority said in a statement on Wednesday. The new concessionaire — which maybe required to invest as much as $1 billion over time — should be on the ground and have taken over the operations of the railway by the end of the first quarter, Zambia Transport Minister Frank Tayali said in an interview Sept. 20.

The move may help revive the near-five-decade old line that Mao Zedong’s government built to be China’s biggest foreign aid project, costing about $500 million. The Tazara railway has since fallen into disrepair and hauls a fraction of its design capacity of about 5 million tons per year.

It’s becoming increasingly strategic as transport routes into and out of a copper-rich region that stretches from Zambia into the Democratic Republic of Congo become clogged.

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The governments of Zambia and Tanzania agreed to bring in a Chinese concessionaire to operate it. The railway may compete with a new one that the US is helping Zambia to build that will connect the so-called copperbelt with an existing line running to the Angolan port of Lobito.

The Tazara line was front and center of Zambian President Hakainde Hichilema’s September state visit to China, Tayali said in the interview in his office in Lusaka. The route requires hundreds of millions of dollars in investment to become profitable, he said.

“This is not a cheap undertaking,” Tayali said. “Over a period of time I could say, look, $1 billion is not far-fetched. It has to be gradual.”

--With assistance from Fumbuka Ng'wanakilala.

(Updates with Zambian transport minister’s comments in second paragraph)