** Shares of GKN Automotive owner Dowlais DWL.L up 1.3% at 72.9p

** RBC raises PT to 100p from 80p; keeps 'outperform' rating

** Says American Axle's AXL.N 1.16 bln pounds ($1.44 billion) cash-and-stock offer undervalues Dowlais

** Estimates combined equity could be worth $3.8-$6.7 bln in ~3 years with Dowlais shareholders getting only $1.5 bln upfront

** DWL shares fell ~18% in the last 12 months ($1 = 0.8055 pounds)

(Reporting by Yamini Kalia in Bengaluru)

((Yamini.Kalia@thomsonreuters.com;))