“Pools of family capital are increasingly transactional with families looking for direct investment opportunities,” said John Studzinski, Blackstone’s ambassador to large family offices and sovereign wealth funds.

To be sure, the rich aren’t abandoning private equity shops as a place to put money. They pour an average of 27 percent of their assets into these funds, according to research firm Preqin. And family money represents 9 percent of private equity funds, more than double from five years ago. Carlyle co-founder David Rubenstein last week said family offices, along with sovereign wealth funds, are the firm’s fastest-growing sources of new money.

Still, an estimated $4 trillion in family capital globally is up for grabs, underscoring why top private equity firms are jockeying for a slice. Blackstone’s Studzinski helps families find transactions and deal flow, which sometimes goes in both directions.

Gianni Versace

For example, the family owners of Gianni Versace SpA wanted to partner with Blackstone when they sold 20 percent of the Italian fashion house to the firm for 210 million euros ($240 million) in 2014.

Carlyle, which manages about $12 billion in family office money, has sometimes partnered with those clients to do deals, a growing trend among buyout managers as they seek other sources of capital for large transactions. That happened with Carlyle’s $7.4 billion acquisition of Symantec Corp.’s Veritas data-storage business, completed in January.

Carlyle, Blackstone and KKR & Co. also regularly host wealthy families at roundtables and dinner meetings around the world.

“The families often have a rich history of being involved in companies -- not somebody who’s been an investor in a particular sector, but somebody who’s lived it," said Mike Arpey, the top fundraiser at Washington-based Carlyle.

Dell, Gates

Some families have been buying companies on their own for decades. MSD Capital, which oversees the fortune of Dell Inc. founder Michael Dell, was formed in 1998 and has over $12 billion under management. Cascade Investment is the secretive holding company dedicated to Microsoft Corp. co-founder Bill Gates’s investments. Pritzker Group, run by J.B. and Tony, has more than 30 dealmakers in Chicago and Los Angeles.