ConocoPhillips Shows Bigger Isn't Better, as Big Oil, Exxon Lag

The unit is the second largest refiner in the U.S., when counting its petrochemicals joint venture with Chevron and its midstream joint venture with Spectra Energy. Of Phillips 66's $5.9 billion in earnings in the last three years, the company's refining & marketing unit accounted for 66% of profit, while chemicals accounted for 20% and midstream 14%, notes Gheit of Oppenheimer.

"Its large and balanced assets portfolio, with more than 80% of the capital employed in the US, provides attractive investment opportunities and a superior risk-return profile, in our view," adds Gheit.

Summing up the analyst bullishness on the ConocoPhillips split in the simplest terms: bigger isn't necessarily better when it comes to the recently stalled Big Oil stock sector.

For more on oil and gas M&A, see 5 energy deals not to be forgotten in 2012 and Chesapeake Energy's flurry of asset sales.

-- Written by Antoine Gara in New York