The Carlyle Group ramped up IPO speculation yesterday, by agreeing to acquire a 55% stake in ESG, an emerging markets equities manager backed by Tiger Global Management. It also closed on around $1 billion in new private equity funds focused on South America (particularly Brazil), and CNBC reports that the firm is meeting with potential underwriters for an offering that could raise as much as $1.2 billion.

    No huge surprises to any of this, since I'm pretty sure Carlyle was rumored to be going public even before Blackstone Group (BX) was rumored to be going public. And, if you're a PE firm looking to IPO, the key is diversification. Large pure-play PE shops like Warburg Pincus or Hellman & Friedman have virtually no shot (and, possibly, no interest).

    In fact, I don't see many other legitimate candidates out there (outside of distressed firm Oaktree, which already is rumored to be prepping an offering). TPG Capital gets mentioned a lot, but it doesn't have too many non-PE business lines. Moreover, it has been generating founder liquidity by selling off small management companies stakes to sovereign wealth funds. It's true that both Blackstone and Carlyle did something similar – and perhaps promised liquidity via IPO – but TPG's moves may the an end rather than a means.

    "It's possible that those institutional investors will at some point pressure a firm like TPG to go public, but they also might just view it as a constant stream of fee revenue," says Colin Blaydon, director of the Center for Private Equity and Entrepreneurship at Tuck School of Business.

    Curious to hear who, if anyone, you think might be next (talking U.S. firms, primarily, here). Bain Capital? Silver Lake? I don't see it, but maybe you do…