Valve has acquired a San Francisco-based start-up founded by former PopCap staffers, and plans to set up a new subsidiary in the area.

Star Filled Studios was founded in September this year by Tod Semple and Jeff Gates. Semple was previously a developer on Plants vs. Zombies at PopCap, and has also worked at LucasArts on Star Wars: The Force Unleashed and on Diablo III with Blizzard North.

Meanwhile, Gates previously worked on Spore at Maxis, and also developed Diablo III and worked at PopCap.

In a statement to Edge, Valve co-founder Gabe Newell confirmed, "The guys who did PvZ, down in the Bay Area, we're helping them set up a Valve subsidiary there."

Newell didn't give any hints regarding what the studio will be tasked with over the coming months. Gamasutra has contacted Semple for confirmation.

This is Valve's second acquisition, the first being Left 4 Dead studio Turtle Rock in 2008 -- although Turtle Rock was slowly broken down afterwards, and eventually revealed that it is working on its own new IP.