0520031

We propose INTEGRAL observations of flaring blazars triggeredby the AGILE gamma-ray satellite. For the first time after CGROit will be possible to observe blazars during high gamma-rayactivity states from a few keV up to a few GeV. This chance willbe crucial to study the simultaneous spectral and temporal behaviourof blazars and to study the synchrotron to inverse Compton (IC)transition region. The gamma-ray (E >100 MeV) flaring duration (few days)is prolonged enough to allow INTEGRAL re-pointing. Quasi-simultaneous observations by INTEGRAL and AGILE of blazars in activestates will be important to establish the IC peak of the nu-Fnuspectra and to study the spectral break in the hard X-ray medium gamma-rayenergy band. We request 300 ksec INTEGRAL ToO observations for each of the first 3 major flares detected by AGILE. A similar proposal (Prop. ID 0420063 P.I. S. Vercellone) was approved with Grade-A as part of INTEGRAL AO-4 but not perfomed because of the AGILE launch delay. [truncated! Please see actual data for full text]