Metals Winners & Losers: Freeport McMoRan

"These incidents at two of the company's highest profile mines, along with the decrease in copper prices, will likely weigh on the near-term prospects for the shares," wrote Anthony Rizzuto, an analyst at investment firm Dahlman Rose, in a research note.

Elsewhere, American Depositary Receipts of the three iron ore giants -- BHP Billiton(BHP), Rio Tinto(RTP) and Vale(VALE) -- all lost ground Monday. Chinese monetary officials indicated a willingness to tighten credit to prevent a bubble, as the country's economy and stock market have surged in the second half of the year.

Word out of one Chinese port, Rizhao, one of the biggest ore importation ports on earth, indicated that volumes would likely drop soon, which is not exactly an earth-shattering prediction. In July, Chinese ore imports reached record levels, and market participants have been attempting to divine all summer whether the surge has resulted from real demand or, rather, from the Chinese stimulus package.

The Shanghai stock market plunged 5.8% Monday, while in Japan the Nikkei index lost 3.1%.

Also complicating matters have been the ongoing ore-price negotiations between Chinese government officials and Rio Tinto, which has been playing point-man for the three mining companies. According to some reports, one Chinese steelmaker has broken away and struck its own deal with Rio, for a 35% price cut from last year's contract. China had been thought to be holding out for as much as a 45% cut.

At Monday's close in New York, Rio's ADRs lost $9.89, or 6.3%, to $148.40; BHP Billiton declined $2.75, or 4.4%, to $60.20; and Vale fell $1.06, or 5%, to $19.65.

Among other metals and mining stocks, Alcoa(AA) fell 86 cents, or 6.5%, to $12.41; Southern Copper (PCU) retreated $1.59, or 5.8%, to $25.92; and U.S. Steel(X) dropped $3.82, or 8.3%, to $42.32.

-- Written by Scott Eden in New York

>To order reprints of this article, click here: Reprints