PLATTSBURGH Registration has begun for the Plattsburgh-North Country Chamber of Commerce Business Expo, which will be held Thursday, June 5, at the State University of New York at Plattsburgh Field House on Rugar Street. With more than 185 booths, the event is the largest business-to-business show in northern New York. The cost for a standard 8 ft. by 10 ft. booth is $375 for chamber members and $475 for those who are not yet members. Electricity and high-speed Internet are available. For more information, call 563-1000 or visit www.northcountrychamber.com.