An earlier version of this article incorrectly characterized Michael Dell’s role in MSD. This has been corrected.
BDT & Company Holdings LLC and MSD Partners LP said they would combine in a merger of two investment firms involving billionaires. The name of the combined firm had not yet been determined. Billionaire Byron Trott of BDT, an investment firm founded by Trott after he became known as the banker for Warren Buffett, will be co-CEO of the combined company, along with Gregg Lemkau, who is CEO of MSD Partners, the investment firm that has emerged from the family office of Dell Technologies Inc. DELL,