Northern Telecom Ltd has scored a breakthrough in the People’s Republic with agreement for a joint venture with the state-owend China Tong Guang Electronics Corp to manufacture the SL-1 family of digital PABXs in Shekou: the Mississauga, Ontario company will have 55% of the venture, which is due to start assembling the 160 to 5,000 line private exchanges at the end of the year, progressively moving over to full manufacture in time.