The group would not officially confirm or deny reports in The Sunday Times and its own paper The Guardian that it is preparing a strategic review in the next few weeks.
But a GMG spokesman said: "In the dynamic and fast changing world of the media, [GMG] regularly reviews its investment portfolio."
He added that GMG had not hired financial advisers to conduct a review and it would be "wrong to speculate on the outcome of any such review".
Trader Media Group declined to comment.
Trader may go in GMG review
The Guardian Media Group (GMG) will conduct a strategic review that could include the sale of Trader Media Print Group, which owns printers Apple Web Offset in Warrington, Acorn Web Off-set in Normanton, West York-shire, and Wiltshire in Bristol.
