WASHINGTON -- The U.S. Department of Justice's antitrust division has subpoenaed Sony's electronics unit for information on its sales of SRAM memory chips. The company expressed its full cooperation with the probe.

The move appears to be part of a growing Justice Department probe into SRAM sales. Earlier this month, Cypress Semiconductor said its SRAM operations were also under investigation.

Sony sold $28 million of worth of SRAM last year. Sony outsources production of the chips.

"Sony intends to cooperate fully with the DOJ in what appears to be an industrywide inquiry," the company said in a statement today.

Separately, the Justice Department has already filed more than a dozen charges against several individuals and makers of DRAM components. In all, more than $730 million in fines has been levied against Samsung, Elpida Memory, Infineon Technologies and Hynix Semiconductor.

The memory industry has historically been tainted with allegations -- and findings -- of price fixing.

Earlier this year Sony was beset by a global recall on its lithium ion laptop batteries.