The Blackstone Group generated some blog attention yesterday for joining Twitter – including from yours truly – but Fortune has learned that there are some larger changes going on at 345 Park Avenue:

First, Blackstone BX has restructured management of its private equity group, installing an eight-person executive committee. The group is broken out by both industry sector and geography, and includes: David Blitzer (relocating from London to New York), Joe Baratta (Europe), Michael Chae (Asia), Prakash Melwani, David Foley, Chin Chu, Neil Simpkins and Garrett Moran.

Firm president and chief operating officer Tony James will continue to be involved with private equity, but is delegating some of his responsibilities via this move.

Chip Schorr

Second, one Blackstone pro notably missing from the new executive committee is Paul “Chip” Schorr, a senior managing director who joined in in 2005 from Citigroup Venture Capital. How come? Because Schorr is leaving Blackstone to form an independent firm focused on mid-market tech investing.

The new shop is expected to raise between $1 billion and $1.5 billion for its debut fund, with Blackstone serving as one of its limited partners. This appears to be only the second time that Blackstone has agreed to seed one of its staffers. The first time was in 1999, when David Stockman left to form Heartland Industrial Partners (hopefully this one will work out better for all involved).

Average equity checks for Schorr’s new firm will be in the range of $60 million to $125 million – the types of deals that a supersized firm like Blackstone cannot really do on a consistent basis. Expect it to compete with tech-focused firms like Francisco Partners and Golden Gate Capital, plus generalists like Summit Partners and TA Associates.

No word yet on who else is part of the launch, but a source says that the initial group will consist of up to 20 investment professionals.

Schorr declined comment, while a Blackstone spokesman declined to comment on either the PE reorg or on Schorr’s pending departure.