According to their about page BTC-e is registered in Bulgaria.
“BTC-e is anything but transparent: it uses third-party banking services to keep its name out of official records. At least one of the banks involved in the process is located in the Czech Republic; the BTC-e site references Bulgaria in its SEO descriptions; the founders, Russian programmers Aleksey and Alexander, honed their skills at the Skolkovo tech park; and the BTC-e managing company is based in Cyprus.”