The most common and most likely answer to this crossword clue is the 6 letter word BUYOUT
I've seen this crossword clue in The Guardian
B
U
Y
O
U
T
Buddy explains!

The straight part
We know that "business deal" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case business deal = buyout.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 BUYOUT mean?
BUYOUT noun- The acquisition of a controlling interest in a business or corporation by outright purchase or by purchase of a majority of issued shares of stock.