It expects the trend will continue as banks face tougher regulation and capital requirements, citing the Basel global banking framework and the U.S. Dodd-Frank changes.
Societe Generale also expects disintermediation to increase, citing Standard & Poor's data estimating global business borrowing needs at $73 trillion through 2018, while banks' lending capacity is only around half that level.
But while disintermediation is strong in the U.S., bank financing has been making a comeback since 2011, it said in a note last week.
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Instead, it sees a "huge potential" for disintermediation in Europe, citing problems with the transmission of low central bank interest rates to bank loans, where margins generally remain high.
With Europe's banks facing an asset quality review later this year and stringent regulatory capital positions, it noted.
"In the slow repair process, euro area non-financial institutions have had to look for new sources of funding," it said. At the same time, "the ECB's commitment to supporting the economy will likely push investors towards higher yielding assets."
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Within Asia, however, interest in the strategy may be limited.
"Traditionally, Asia has been funded by bank loans," Clifford Lee, head of fixed income at DBS, said.
"Banks continue to be well-funded in the region. The loan markets have their ups and downs, but they're still quite healthy," he said, noting this is a factor hampering the development of bond markets in the region.
While the strategy was more common before the global financial crisis, "the 2008 crisis saw that end in tears for hedge funds and those still have recent memories so we don't see the return of high-yield private debt coming back in a big way," Lee said.
Others are also skeptical that disintermediation will catch on as a trend.
"Because the bond markets are so alive and kicking, the need for companies to go to the private space is also lower," Harsh Agarwal, head of Asia credit research at Deutsche Bank, said, noting that Asia's bond issuance so far this year is around $105 billion, compared with around $125 billion for all of 2013. "If you get a rating, you could easily come to the bond market and raise money, so why go to the private market? I would guess the pie is smaller now than it was 4-5 years back," during the credit crisis.
— By CNBC.com's Leslie Shaffer. Follow her on Twitter @LeslieShaffer1