Revenues from the company’s Buy segment decreased 6% to $755m in Q3 compared to Q3 2017. Revenues from the developed markets for the Buy division fell by 2%, which the company attributed to pressure on the US consumer goods industry.

The Watch segment fared slightly better, with a revenue increase of 0.8% to $845m, with revenues for audience measurement of video and text up by 4.7%.

In July, Nielsen announced it was reviewing its Buy segment, which tracks consumer purchases. The company later said it was expanding the strategic review to include the whole business, as it explores a potential sale, although no timescale has been shared publicly.

Dave Anderson, chief financial officer, said: "We are making good progress on efficiency initiatives which are generating increased net productivity in 2018. We are reiterating our 2018 guidance for revenue, adjusted EBITDA, and GAAP EPS. However, we are lowering our 2018 free cash flow guidance from $550-$575m to $450-$500m due to continued working capital headwinds."

Jim Attwood, executive chairman of the board, said: "The board of directors, with the assistance of our advisors and management team, is focused on the expanded strategic review that we announced in September, which includes a broad review of strategic alternatives for Nielsen and its businesses."