Context :

Aims : The main goal of this work is to a have a new neutral hydrogen ( H I ) supershell candidates catalog to analyze their spatial distribution in the Galaxy and to carry out a statistical study of their main properties .

Methods : This catalog was carried out making use of the Leiden-Argentine-Bonn ( LAB ) survey .
The supershell candidates were identified using a combination of two techniques : a visual inspection plus an automatic searching algorithm .
Our automatic algorithm is able to detect both closed and open structures .

Results : A total of 566 supershell candidates were identified .
Most of them ( 347 ) are located in the second Galactic quadrant , while 219 were found in the third one .
About 98 \% of a subset of 190 structures ( used to derive the statistical properties of the supershell candidates ) are elliptical with a mean weighted eccentricity of 0.8 \pm 0.1 , and \sim 70 \% have their major axes parallel to the Galactic plane .
The weighted mean value of the effective radius of the structures is \sim 160 pc .
Owing to the ability of our automatic algorithm to detect open structures , we have also identified some “ galactic chimney ” candidates .
We find an asymmetry between the second and third Galactic quadrants in the sense that in the second one we detect structures as far as 32 kpc , while for the 3rd one the farthest structure is detected at 17 kpc .
The supershell surface density in the solar neighborhood is \sim 8 kpc ^ { -2 } , and decreases as we move farther away form the Galactic center .
We have also compared our catalog with those by other authors .

Conclusions :