A sign board is seen near the Sibanye gold mine in Westonaria, west of Johannesburg, South Africa, April 6, 2016. REUTERS/Siphiwe Sibeko/File Photo

JOHANNESBURG (Reuters) - Sibanye Gold Ltd SGLJ.J said it might tap shareholders for up to $1.3 billion to partly fund a $2.2 billion takeover of Stillwater Mining Co SWC.N, the only U.S. miner of platinum and palladium.

Sibanye had initially said it would raise around $750 million via a rights issue to help to fund the deal, but said on Friday it had reconsidered after some shareholders expressed concerns about the company’s debt levels.

Shares in Sibanye fell more than 4 percent at the market open before paring loses. By 0716 GMT, they were down 3 percent at 30.20 rand.

“Sibanye believes that increasing the equity component would be prudent in the current strong rand environment, allowing the company to maintain a strong balance sheet,” it said in statement accompanying a half-year trading update.

Sibanye’s proposed takeover offer for Stillwater will increase South Africa’s grip over global platinum and palladium supply and underline chief executive Neal Froneman’s determination to branch out of gold mining and South Africa.

The bullion and platinum producer said gold production of 765,000 ounces for the six months to December 31 was similar to the amount produced in the six months ended June 30 2016, while platinum group metal production amounted to 230,000 ounces.

Sibanye said the consensus outlook for precious metal prices in the near term, particularly in rand terms, was subdued and further sustained rand strength would impact on operating margins in its gold and platinum divisions.