The most common and most likely answer to this crossword clue is the 6 letter word CARTEL
I've seen this crossword clue in Financial Times
C
A
R
T
E
L
More clues leading to the result CARTEL
- What determines price of wagon on railway
- Vehicle hired out for returning syndicate
- Political alliance suggesting auto phone system
- Syndicate for clarinet not in fashion
- Association makes claret
- Political bloc spilling claret
- Clubs, later, reformed syndicate
- Worry about Tory leader joining large organisation restricting free trade
- Finally changing sides, US president establishing trade body
- Syndicate‘s caution about time taken by learner
Buddy explains!

The straight part
We know that "trade body" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case trade body = cartel.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CARTEL mean?
CARTEL noun- A group of businesses or nations that collude to limit competition within an industry or market.
- A combination of political groups (notably parties) for common action.
- A written letter of defiance or challenge.
- An official agreement concerning the exchange of prisoners.
- A ship used to negotiate with an enemy in time of war, and to exchange prisoners.