Fermi Inc. has won the backing of its second-largest shareholder as its former chief executive officer seeks a special meeting to seize control of the data-center developer’s board.

Caddis Capital, which owns a 9.3% stake, supports the ousting in April of former CEO Toby Neugebauer and opposes his push to appoint new directors and put the company up for sale, according to a statement reviewed by Bloomberg News.