* Q1 EPS $0.55 in line with estimates . * Q1 rev of $552.9 mln misses estimates of $595.6 mln * Cuts 2009 earnings view * Shares fall as much as 13 percent (Adds conference call details, analyst comments, updates share movement) By Bhaswati Mukhopadhyay BANGALORE, April 21 (Reuters) , Electronic instruments maker Ametek Inc ( AME.N ) posted a 11 percent decline in net profit that was in line with market estimates, but cut its 2009 earnings outlook on what it sees as a challenging year ahead, sending its shares down as much as 13 percent. The company, which also makes electric motors, now sees 2009 earnings of $2.10 to $2.25 a share, down from its prior view of $2.40 to $2.60 a share. "The management is being conservative, but that is reasonable in this environment," analyst Antonio Antezano of Macquarie Research said.