Whats the name of the famous hostile takeover where the winner payed less than the loser
With the help of a former fellow student I was able to find out some details.
The anecdote was about the following three companies:

Macy's, Inc.
Robert Campeau
Federated (covered in the article about Macy's)

Some news coverage exists:

https://mindyourdecisions.com/blog/2011/09/20/when-game-theory-backfires-a-case-study-of-robert-campeaus-takeover-bid/
https://archive.fortune.com/magazines/fortune/fortune_archive/1990/06/18/73686/index.htm

In short, Macy's offered \$67 per share contingent on getting a majority of shares. Campeau offered \$74 per share if less than half was tendered, otherwise $\frac {0.5}{x} * \\\$74 + \frac {x - 0.5}{x} * \\\$60$ with $x$ the fraction of shares offered to Campeau. It seems as if the bidding war continued a bit after this scheme. The prices given in the blog above differ, I am sticking to these from the lecture.
I am very grateful for having had the opportunity to attend Prof. Kirste's lectures at the Universität Rostock. They were full of impressive details like this gem here.