  Since November 2002, we have conducted the largest deep imaging survey of the
young, nearby associations of the southern hemisphere. Our goal is detection
and characterization of substellar companions at intermediate (10--500 AU)
physical separations. We have observed a sample of 88 stars, mostly G to M
dwarfs, that we essentially identify as younger than 100 Myr and closer to
Earth than 100 pc. The VLT/NACO adaptive optics instrument of the ESO Paranal
Observatory was used to explore the faint circumstellar environment between
typically 0.1 and 10''. We report the discovery of 17 new close (0.1-5.0'')
multiple systems. HIP108195AB and C (F1III-M6), HIP84642AB (a~14 AU, K0-M5) and
TWA22AB (a~1.8 AU; M6-M6) confirmed comoving systems. TWA22AB is likely to be a
astrometric calibrator that can be used to test evolutionary predictions. Among
our complete sample, a total of 65 targets observed with deep coronagraphic
imaging. About 240 faint candidates were detected around 36 stars. Follow-up
observations VLT or HST for 83% of these stars enabled us to identify a
fraction of contaminants. The latest results about the substellar companions to
GSC08047-00232, AB Pic and 2M1207, confirmed during this survey and published
earlier, are reviewed. Finally, the statistical analysis of our complete set of
coronagraphic limits enables us to place constraints on the physical and
properties of giant planets between typically 20 and 150 AU.
