We present the results of a new analysis of data taken in 1998-2002 for a search for high-energy extraterrestrial neutrinos .
The analysis is based on a full reconstruction of high-energy cascade parameters : vertex coordinates , energy and arrival direction .
Upper limits on the diffuse fluxes of all neutrino flavors , predicted by several models of AGN-like neutrino sources are derived .
For an { \bf E ^ { -2 } } behavior of the neutrino spectrum , our limit is { \bf E ^ { 2 } F _ { \nu } ( E ) < 2.9 \times 10 ^ { -7 } } cm { { } ^ { -2 } } s { { } ^ { -1 } } sr { { } ^ { -1 } } GeV over a neutrino energy range { \bf 2 \times 10 ^ { 4 } \div 2 \times 10 ^ { 7 } } GeV .
This limit is by a factor of 2.8 more stringent than a limit obtained with a previous analysis .