Over the past three months, ConocoPhillips (NYSE: COP) has experienced a 12.6% fall, underperforming the industry’s 3.9% decline. Recent investor concerns primarily stem from the premium ConocoPhillips is set to pay for acquiring Marathon Oil Corporation (NYSE: MRO) and the expected increase in debt due to this transaction. Image Source: Zacks Investment Research MRO Deal Seems Expensive at First Glance: Cause for Concern?On May 29, ConocoPhillips finalized an agreement to acquire Marathon Oil in an all-stock deal valued at $22.5 billion, which also incorporates $5.4 billion in net debt. Accor…