Energy Winners and Losers: Exxon Mobil

Noble shares rose 81 cents, or 3.4%, to $24.98. Ensco shares lifted 93 cents, or 3.9%, to $25.20. Shares of Rowan gained 37 cents, or 3.3%, to $11.58. Transocean shares rose $2.42, or 4.2%, to $59.62

Dell also upgraded exploration and production companies Talisman Energy (TLM Quote) and Chesapeake Energy (CHK Quote) to "Outperform" from "Market Perform." Both companies have underperformed during the recent commodity price volatility, Talisman due to its lower quality, higher cost operations and Chesapeake due to its elevated leverage and forced asset sales.

However, Dell said he expects the likely rebound in gas prices midyear 2009 and the growing appetite for energy beta stocks to drive a reversal in these trends.

Talisman shares lifted 18 cents, or 2.1%, to $8.96. Shares of Chesapeake rose 34 cents, or 2.1%, to $16.72.

While Dell spoke glowingly about many energy stocks, he downgraded Exxon Mobil (XOM Quote), the world's largest publicly traded oil company, and Occidental Petroleum (OXY Quote) as he views both stocks as overvalued compared to the market.

"(Exxon Mobil's) strong balance sheet and top notch credit rating have driven significant outperformance but catalysts for investors to put additional money into the name appear low," he said.

Still, shares of Exxon Mobil rose 22 cents to $72.16, while Occidental fell 23 cents to $51.31.