ConocoPhillips announced on Wednesday that it will buy Marathon Oil in an all-stock deal valued at $22.5 billion, including debt.  Marathon Oil shareholders will receive 0.2550 shares of ConocoPhillips for each share of Marathon Oil common stock. Under the agreement, ConocoPhillips will receive additional acreage to its existing U.S. onshore portfolio, adding over 2 billion barrels of resource.Ticker Security Last Change Change % COP CONOCOPHILLIPS 118.96 +1.71 +1.46% "This acquisition of Marathon Oil furt ...