Yum! plans to buy China's 'Little Sheep' chain
A sign shows Yum! Brands Inc's support center at its corporate headquarters in Louisville. Reuters

Rio Tinto Plc, Yum! Brands, Newmont Mining Corp, eBay Inc, Edwards Lifesciences, Unisys Corp, Superconductor Technologies, ARM Holdings and Opko Health Inc. are among the companies whose shares are moving in the pre-market trading on Wednesday.

Gainers

Rio Tinto Plc (NYSE:RIO) stock surged 4.34 percent to $46.18 in pre-market trading. The stock has a 52-week low of $41.59, a 52-week high of $60.45 and $81.76 billion in market capitalization.

Yum! Brands Inc. (NYSE:YUM) stock surged 3.68 percent to $66.51 in pre-market trading. The company reported first quarter net profit of $337 million or $0.72 per share, down from $458 million or $0.96 per share in the same quarter a year earlier. Adjusted profit declined to $0.70 per share from $0.76 per share last year but topped analysts’ estimate of $0.60 per share.

Newmont Mining Corp. (NYSE:NEM) stock gained 1.73 percent to $32.99 in pre-market trading. The stock has a 52-week low of $31.77, a 52-week high of $57.93 and $16.11 billion in market capitalization.

eBay Inc. (NASDAQ:EBAY) stock advanced 1.03 percent to $53.03 in pre-market trading. The stock has a 52-week low of $38.00, a 52-week high of $58.04 and $68.12 billion in market capitalization.

Losers

Edwards Lifesciences Corp. (NYSE:EW) stock tumbled 15.47 percent to $70.00 in pre-market trading. Its first quarter adjusted net profit rose to $0.72 from $0.53 per share in the same period last year but fell short of Reuters' estimate of $0.76 per share. Edwards Lifesciences also lowered its fiscal 2013 adjusted earnings guidance to a range of $3.00 to $3.10 per share on revenues of $2.0 billion to $2.1 billion from its prior estimation of $3.21 to $3.31 earnings per share on revenues of $2.1 billion to $2.2 billion.

Unisys Corp. (NYSE:UIS) stock tumbled 14.92 percent to $17.50 in pre-market trading. The company swung to first quarter net loss of $33.9 million or $0.77 per share compared to a net profit of $13.4 million or $0.30 per share in the same period last year. Quarterly revenues plunged 13 percent to $810.4 million and also missed analysts' estimate of $852.25 million.

Superconductor Technologies Inc. (NASDAQ:SCON) stock plunged 6.79 percent to $5.08 in pre-market trading. The stock rallied nearly 135 percent in regular trading Tuesday after the company announced that it has recently received purchase orders from multiple customers for its Conductus (R) 2G HTS wire.

ARM Holdings Plc (NASDAQ:ARMH) stock plunged 3.43 percent to $44.73 in pre-market trading. The stock has a 52-week low of $21.64, a 52-week high of $46.87 and $21.32 billion in market capitalization.

Opko Health Inc. (NYSE:OPK) stock plunged 3.40 percent to $6.82 in pre-market trading. Opko Health and PROLOR Biotech Inc announced on Wednesday that both the companies have signed a definitive merger agreement under which Opko will buy PROLOR in an all-stock transaction valued at approximately $480 million. Holders of PROLOR common stock will receive 0.9951 shares of OPKO common stock for each share of PROLOR common stock.