Morgan Stanley analysts Benjamin Swinburne, Maria Ripps and James J. Luan downgraded Omnicom Group Inc. OMC from Equal-Weight to Underweight and lowered th price target from $86 to $72 Monday. They also lowered the price target for Interpublic Group of Companies Inc IPG from $24 to $22. Swinburne, Ripps and Luan lowered estimates for both companies on deceleration in organic growth, which is driven by pressure in key advertising verticals, like retail and CPG. The analysts believe current analyst consensus estimates for organic growth are too high, adding that year-over-year organic growth is already negative in the U.S. market. The analysts are also skeptical about margin expansion, which seems to be the consensus on the Street. Read moreOMC: There is a breakout of the rising channel, so some downside may take place. $OMC, Omnicom Group Inc. / D IPG: There was a breakout of the falling channel, so more upside or some consolidation are possible. $IPG, Interpublic Group of Companies, Inc. (The) / D