(RTTNews) - Pan American Silver (PAAS: News ) gapped open slightly lower Wednesday and declined during the first 2 hours of trade. The stock slipped further late in the afternoon and closed down by 1.50 at $20.40.

Peabody Energy Corp. said Thursday that it expects production at its North Goonyella Mine in Queensland to resume in four to six weeks, following a mid-August roof fall at the mine.

OJSC Norilsk Nickel Mining and Metallurgical Co. (NILSY.PK: News ) Friday said it has proposed to buy back 15 percent of its stake held by Russian aluminium firm UC Rusal for $8.75 billion. As per the offer, Norilsk Nickel, Russia's largest

Arch Coal Inc.'s (ACI: News ) second-quarter net income plummeted to $11.1 million or $0.06 per share from $66.2 million or $0.41 per share a year earlier. Excluding charges, adjusted net income for the second quarter of 2011 was $78 million, or $0.44 per share, the company said. On average, 22 analysts polled by Thomson Reuters expected earnings per share of $0.60 for the quarter.

Mining equipment maker Joy Global, Inc. (JOYG: News ) is close to acquiring Chinese coal-mining equipment maker International Mining Machinery Ltd. (ICMHF.PK), according to Bloomberg on Wednesday.