The MF indicates that it emanated from the Ministério da Fazenda (Ministry of Finance).

I think that by far the best equivalent of Portaria is Statutory Instrument because it is an equivalent term rather than just a translation

This term is hard to translate and many translators disagree. The lead translator at the Brazilian Embassy in Washington prefers "Ministerial Directive" but others insist on "order." However, the same translator said that "order" in American English bureaucracy may be confused with a U.S. government "executive order," which affects ONLY actions taken within the federal (or state) executive branch of government. Law firm I worked for in Brazil (decades ago) defined Portaria as : "a written ruling through which the cabinet ministers regulate the activities of their ministries. Used to promulgate regulations needed to complement or clarify some aspect of a law or decree-law. It has very nearly the force of law)."
I personally have stuck with "directive," including the name of the ministry that issued it. It's up to the individual translator, nothing is "carved in stone" as far as I know.

By the way, ProZ told me this query is not within my area of expertise, because it was classified as "marketing" - actually it might better have been classified under "law"