0000899243-01-500156 DEF 14A 1 20010524 20010424 QUANTA SERVICES INC 0001050915 1731 742851603 DE 1231 DEF 14A 34 001-13831 1609318 1360 POST OAK BLVD SUITE 2100 HOUSTON TX 77056 7133506000 1360 POST OAK BLVD SUITE 2100 HOUSTON TX 77056 DEF 14A 1 ddef14a.txt DEFINITIVE PROXY MATERIALS