I am searching for 5 business cases (or more) where company A acquired
company B (or A & B merged) and selected the name of company A as the
new corporate brand. But I need business cases where the new company
sold the old corporate brand name (the trademark) of company B to
another company C. This is a special case, in many cases the name of B
would just disappear.

A couple of years ago, Seagram, the large liquor company, was bought
out by liquor giant Diageo, (Guiness, Smirnoff, Cuervo, etc.). At that
time, a number of Seagram's brands had to be sold off to satisfy
monopoly trade laws. Although Diageo kept Seagram's 7-crown and
Seagram's V. O., Seagram's Gin was among the products Diageo sold off,
acquired by French company Pernod-Ricard.