The U.S. energy sector is witnessing an intensifying standoff as Phillips 66 $PSX has formally rejected a proposal from Elliott Investment Management to break up the company. In a letter set to be published, Phillips 66 questioned the objectivity behind Elliott’s push for a split, underscoring concerns over a potential conflict of interest. The issue centers around Elliott's simultaneous efforts to acquire Citgo Petroleum, one of Phillips 66’s key competitors.