The US Department of Justice is probing Sony's electronics unit as part of an industry-wide investigation into sales of a particular type of memory chip, an Associated Press report said.
The news could spell more trouble for a company already stung by sinking profits, a global battery recall and product delays, the report said.
Sony received a subpoena from the Justice Department's antitrust division seeking information about Sony's static random access memory, or SRAM, business, company spokesman Atsuo Omagari, quoted in the Associated Press report, said.
'Sony intends to cooperate fully with the DOJ in what appears to be an industry-wide inquiry,' the company said in a short statement.
Separately, EU antitrust regulators said they had raided several chip makers in Germany in October as part of a price-fixing investigation regarding SRAM chips, the report said.
Earlier in October, US-based chipmaker Cypress Semiconductor said its SRAM operations were also under investigation by the US Department of Justice.
SRAM is a kind of computer memory that is faster and more reliable than the more extensively used DRAM.
A separate DOJ investigation into price-fixing among DRAM companies has so far resulted in more than a dozen charges against individuals and more than $731 million in fines against Samsung Electronics, Elpida Memory, Infineon, and Hynix Semiconductor, the report said.