The FTC was scheduled to make a decision last week on whether to sue to block the tie-up and newspapers reported that sports broadcaster ESPN could be the key to the takeover.

In April, Arbitron shareholders voted in favour of the radio ratings firm’s acquisition by Nielsen, the dominant provider of TV measurement services, but the Disney-owned sports broadcaster licences software from Arbitron to measure how many viewers watch the network and on which device.

According to the New York Post, with the licence due to expire soon, ESPN may block the takeover if it is unable to continue licencing the software and added that ESPN’s senior VP Artie Bilgrin had been in talks with the commission.

In a statement, Nielsen said: “The regulatory process continues to progress and Nielsen continues to be confident in the ultimate outcome.”