Blackstone Seeks About $15 Billion for New Secondaries Funds

Blackstone Group Inc. is seeking to raise about $15 billion for two new investment funds in the fast-growing private equity secondaries market.

Blackstone Strategic Partners, a $38 billion unit focused on investing in existing private equity portfolios, aims to raise $12 billion to $13 billion for a ninth flagship fund, which would be its biggest ever, and a smaller vehicle of at least $2 billion to focus on so-called general partner-led secondary deals, according to people familiar with the plans.

The firm’s secondaries business grew roughly eightfold over the past six years and should continue to expand at a “very ...