The firm’s largest investors have been in talks about the strategic options. : Guggenheim Partners is exploring the sale of a stake in its $250 billion asset-management unit overseen by Scott Minerd, according to people familiar with the matter. Guggenheim Partners Investment Management has been in talks with global insurers, sovereign wealth funds and investment pools in Europe, the Middle East and Asia, the people said. The Wall Street Journal reported Wednesday that the deal could involve Guggenheim taking on German insurer Munich Re’s asset management unit.