Shares of

PalmSource

(PSRC)

surged after Japan's

Access Co.

agreed to acquire the software licensor for $324 million.

Access, which sells content delivery and Internet access software, will exchange $18.50 in cash for every PalmSource share outstanding. PalmSource closed at $10.09 Thursday and was recently up $7.91, or 78%, to $18 in premarket Instinet trading.

Speculation that PalmSource could end up as a takeover target

was fueled in May when the company signed a five-year licensing agreement with its former corporate sister,

PalmOne

(PALM)

. The company has replaced its CEO, CFO and chairman over the last year.

Both PalmSource and PalmOne were formerly part of Palm. PalmOne spun off PalmSource and changed its name as part of its acquisition of Treo developer Handspring in 2003.

"The combination of Palm OS with Access' software products is expected to give Access one of the broadest lines of mobile software in the industry, as well as extend its market opportunity," Access said in a release. "With this acquisition, Access gains operating system platform expertise and Linux development resources for mobile devices in the U.S., France and China."