PERTH (miningweekly.com) – Belgium's Nyrstar has upped its bid for Australian zinc and lead-miner CBH Resources, after its original bid was rejected in December.

The world's biggest zinc producer increased its offer to A$0,19 a share, from the initial A$0,13 a share, after it had undertaken an “extensive” amount of work to improve the offer, it reported on Friday.

Nyrstar said that its revised offer for CBH was superior to the offer made by major shareholder Toho Zinc, under which CBH’s Rasp zinc/lead/silver project, in New South Wales, would be jointly developed.

"There is no certainty that the Rasp project will be developed under the Toho proposal, and even if it is developed, it is unclear how CBH will fund its 50% share of the estimated project capital."

The revised proposal would proceed by scheme of arrangement and would apply to all the issued ordinary share capital of CBH, as well as any ordinary share that was issued up to the date of the acquisition.

Nyrstar is demanding a response from CBH before the start of trading on Monday, stating that it would need a sufficient period of time to complete its due diligence, before CBH’s scheduled general meeting at the end of the month.

CBH responded that it would provide a preliminary response to Nyrstar early next week. A further decision on whether to proceed with the shareholder meeting at the end of March, as well as a consideration on the Toho transaction, was expected to be made shortly, the Australian company said.

Last year, Nyrstar unveiled a strategy to integrate its smelting business by expanding into mining operations. It had since acquired three zinc mines in the US from the Glencore Group and agreed to take a 19,9% stake in Ironbark, an Australian company developing a zinc/lead deposit in Northern Greenland.

In January, the Belgium company agreed to buy zinc concentrate from Talvivaara, while it would supply the Finnish company with sulphuric acid for its leaching processes.