Slacker, which develops portable radio players users can program according to their musical tastes, has raised $9.6 million of a $10.2 million round, according to a regulatory filing released yesterday. Funds were first raised on April 30, 2009, and the company has since raised the $9.6 million from nine investors. The filing did not specifiy whether these were new or existing investors—the latter include Centennial Ventures, Rho Ventures, Austin Ventures, Mission Ventures and Sevin Rosen Funds.  We contacted the company for further details, but the CEO wouldn’t comment.

Slacker launched in early 2007 with about $13.5 million in venture funding, then raised another $40 million in a second round in mid-2007. According to regulatory filings the company raised another $5 million toward the end of 2008.  If the company reaches its $10.2 million goal, it would bring total funds raised to date to $68.7 million.

Slacker made a splash in early 2007 when it launched at the SXSW music festival in Austin, Texas. (I was there and remember a futuristic lounge and what seemed like an army of attractive women handing out Slacker merchandise and promotional material.)  Recently it has expanded by launching iPhone and BlackBerry applications.  It also has discovery qualities to it, like rival Pandora, where users can type in artist names and have similar music played to them.

• Digital Music Service Slacker Gets $5 Million Bridge Round