Ajit Shah, former general partner at Worldview Technology Partners, has put together a different kind of firm to make seed-stage investments in start-ups.

Called Ariva, its model is like a federation of investors — that is, more formal than an angel alliance but less structured than a typical VC firm. The goal is to allow partners to spend more time working with entrepreneurs.

Word has been out since last year that Shah was raising the fund, but his firm came out of “stealth” mode with a piece earlier today at PEHub. Shah has joined with Robert Simon, formerly of Alta Partners, and will raise a $150 million inaugural fund. In some cases, the firm will also make follow-on rounds.

Shah also talked with VentureBeat this morning. Shah is known for his style of avoiding the hectic multiple board-seat style of many larger venture firms. During the boom years, and then after the bust in 2000, he steadfastly refused to carry a cell phone for example. He left the large venture capital firm, Worldview, a few years ago, when that firm began having internal problems. Like many firms, WorldView had raised vast amounts of money, and struggled to find good start-ups to invest it in. Shah said believed the VC model was headed in the wrong direction, and wanted to return to the basics of building companies by working more closely with entrepreneurs.

Reflecting his style, his firm will limit the number of portfolio company board seats per partner to a maximum of three. This will allow partners to be able to spend at least a day a week working with each startup. (Many larger firms have partners holding ten or more board seats).

More radically, however, it has introduced a sort of federation of investors, a group that will invest on behalf of the fund, but will have fewer duties in its day-to-day management. Ariva will split the “carry,” or profits, in half with these associated investors, who will be more independent and spend more time with companies than is typical at most venture capital firms. That’s different from the 1 percent or so that bigger venture firms give to “venture partners” who don’t have fund management responsibilities.

Shah and Simon have recruited six such venture partners, each with a mandate to coach entrepreneurs, helping them with a mixture of company founding experience, industry knowledge relevant to the specific entrepreneur, and operating background. Each partner will invest between $15 million to $20 million. Ariva will cover their expenses, but will not pay partners a salary. They are the following:

–Andy Ludwick, former CEO of Bay Networks,
–Mike Pliner, co-founder of software developer Verity,
–Kumar Ganapathy co-founder of VxTel,
–Jeff Clavier, a software venture capitalist,
–Sass Somekh, former president of semiconductor equipment maker Novellus,
–Teddy Shalon, founder of drug developers Synteni and Neosil.

Ariva has already invested in Virident Systems, which makes low-power servers for Internet applications, and Osteogenix, a bone therapy company.

Here is a one-page overview of the firm’s strategy.