Context : Thanks to its proximity , \alpha Centauri is an outstanding target for an imaging search for extrasolar planets .

Aims : We searched for faint comoving companions to \alpha Cen located at angular distances of a few tens of arcseconds , up to 2-3 arcmin .

Methods : We obtained CCD images from the NTT-SUSI2 instrument in the Bessel V , R , I , and Z bands , and archive data from 2MASS .

Results : We present a catalogue of the detected objects inside a 5.5 arcmin box around this star .
A total of 4313 sources down to m _ { V } \approx 24 and m _ { I } \approx 22 were detected in the SUSI2 images .
The infrared photometry of part of these sources has been extracted from the 2MASS images .

Conclusions : No comoving companion to \alpha Centauri were detected between 100 and 300 AU , down to a maximum mass of \approx 15 times Jupiter .
We also mostly exclude the presence of a companion more massive than 30 M _ { J } between 50 and 100 AU .