Trade and oil supply interrupted by current leader (9)
I believe the answer is:
editorial
'leader' is the definition.
(type of newspaper article)
'trade and oil supply interrupted by current' is the wordplay.
'and' says to put letters next to each other.
'supply' indicates anagramming the letters (in a supple way).
'interrupted by' indicates putting letters inside.
'current' becomes 'I' (physics symbol).
'trade' after 'oil' is 'oiltrade'.
'oiltrade' with letters rearranged gives 'editoral'.
'editoral' going around 'i' is 'EDITORIAL'.
(Other definitions for editorial that I've seen before include "Newspaper opinion piece" , "Chief newspaper article" , "Article written" , "Article expressing the views of the publication" , "paper item" .)