Shares of Giant Industries ( GI) were among the NYSE's winners Monday, climbing 14% after the oil refiner agreed to be acquired by Western Refining ( WNR) for $1.2 billion.

Western will pay $83 a share in cash, a premium of 16% over Giant's Friday closing price of $71.79. The purchase, which also will include the assumption of $275 million in debt, will make Western the fourth-largest publicly traded independent refiner and marketer in the U.S.

"With Giant, we will significantly increase our capacity in fast-growing, high-demand areas and gain an immediate footprint in new, complementary businesses," Western said. The transaction will be funded by about $250 million in cash on hand and a $2 billion loan package from Bank of America. The deal is expected to close in the fourth quarter. Shares of Giant recently were trading up $9.90 to $81.69, while shares of Western fell 29 cents to $25.70.

Kinder Morgan ( KMI - Get Report) rose 2% after the company agreed to be acquired for $15 billion, or $107.50 a share, by a group of investors that includes Kinder Morgan's CEO and its co-founder. The all-cash deal represents a 6% premium over Friday's closing price of $101.70 and a 27% premium over the company's closing price of $84.41 on May 26, which was the last trading day before the group of investors first announced its proposal to take the company public. The private equity firms also will assume about $7 billion in debt. The deal is expected to be completed by early 2007. Shares were up $2.50 to $104.20.

Amazon.com ( AMZN - Get Report) rose 3% after the Internet retailer announced a $500 million stock buyback plan. Shares will be purchased over the next 24 months. "The program allows the company to opportunistically repurchase its shares," Amazon said. "The company may do so if it believes its shares are undervalued." Shares recently changed hands at $28.79, up 76 cents.

Shares of Charming Shoppes ( CHRS - Get Report) jumped 8% after Standard & Poor's said it plans to add the retailer to its S&P MidCap 400 index after the close of trading Monday. Charming Shoppes will replace Gtech Holdings which is being acquired by Lottomatica. Shares of Charming Shoppes were adding $1 to $12.84.

Wal-Mart ( WMT - Get Report) shares rose 1% after the retailer said August same-store sales rose 2.7%, at the high end of its previous guidance. Previously, the company forecast a gain of 1% to 3%. In July, Wal-Mart's same-store sales rose 2.4%. Shares were trading up 61 cents to $44.49.

U.S. Steel ( X) fell 2% after Prudential downgraded shares of the company to underweight from neutral. The firm also reduced its price target to $50 from $65. Prudential cited near-term steel industry oversupply concerns for its downgrade. Shares were trading down $1.42 to $58.26.

Shares of Brown-Forman ( BFB) fell modestly after the liquor and beer company announced an agreement to buy a Mexican tequila business. Brown-Forman will buy most of the assets of Grupo Industrial Herradura for $876 million. The purchase includes the Herradura and El Jimador tequilas and the New Mix tequila-based ready-to-drink brand.

"While Brown-Forman has had a variety of interests in Mexico for many years, the acquisition of Casa Herradura is our most significant investment in the country and will enable us to continue our company's international expansion," the company said. Brown-Forman expects the deal to add 8 cents to 12 cents a share to fiscal 2007 earnings. Shares recently were trading at $73.45, down 61 cents.

NYSE volume leaders Monday include Lucent Technologies , up 5 cents to $2.28; Ford ( F), up 3 cents to $8.03; Exxon Mobil ( XOM), down 30 cents to $70.13; DirecTV ( DTV), down 2 cents to $18.61; Pfizer ( PFE), up 17 cents to $27.40; Nortel Networks , up 3 cents to $2.15; Advanced Micro Devices, up 11 cents to $24.67; and Wyeth , up 62 cents to $48.28.

Nasdaq volume leaders included Intel ( INTC), up 31 cents to $19.21; Sun Microsystems ( SUNW), up 10 cents to $4.95; JDSU ( JDSU), up 8 cents to $2.66; Apple ( AAPL), down 71 cents to $68.04; Microsoft ( MSFT), unchanged at $25.85; eBay ( EBAY), up 63 cents to $25.93; Avanex , up 30 cents to $1.94; and Dell ( DELL), up 50 cents to $22.26.