The current-voltage characteristics and electrical switching behaviour of bulk As_xTe_100-x-ySe_y glasses have been investigated over a wide composition range (25<or=x<or=60;10<or=y<or=25). Most of the glasses studied have been found to exhibit a current-controlled negative-resistance behaviour with memory. A sharp switching is observed in the glass of composition As₅₀Te₃₀Se₂₀. A strong dependence of the switching fields on composition, which resembles the variation of crystallization temperatures with x, has been noticed. Further, a current pulse of 100 mA amplitude and 10 mu s duration is found to re-set the memory-switched As-Te-Se glasses to the original high-resistance state. The sample can be made to switch again, with +or-2% variation in the switching fields. This indicates the possible application of these materials in 'read mostly' memories.