Television bosses want the duo to provide "fireworks" on the talent show and are planning on bringing back Nicole Scherzinger as a judge, The Sun reports.
The popstar pair fell out when Williams quit Take That in 1995 but have since made-up when the Angels and Rock DJ singer rejoined his bandmates in 2010 for a new album and string of sell-out concert dates.
A spokesman for the show said: "It's far too early to say anything about the judging panel for this year's X Factor."
Robbie Williams has teased fans with the prospect of another reunion with Take That pal Gary Barlow after posting a picture online of the two of them rehearsing.
The duo are seen singing on a podium together surrounded by musicians in the image which was posted on Twitter earlier today, sparking speculation they will perform in the next few days.
The photo is accompanied by the caption: "Robbie and the Captain - what are they up to?"
Williams was reunited with his erstwhile bandmate earlier this month when they teamed up as Barlow was celebrated with a Music Industry Trusts Award at a gala dinner.
Both performers are due to play solo shows in the coming days. Williams is on the bill for the Royal Variety Performance on Monday and will play headline shows at London's O2 Arena from Thursday.
X Factor judge Barlow is to perform a Little Noise Sessions show for Mencap on Monday at east London's St John-at-Hackney Church, and is also playing a series of shows throughout this month and through to January as part of his first solo tour for 13 years.
Gary Barlow has been honoured with the Music Industry Trust Award at a prestigious bash in central London.Read the full story ›
Singer Robbie Williams turned on the Christmas lights in Oxford Street and laughed off claims his hit song sounds like a sweets advertRead the full story ›
Robbie Williams is celebrating his first solo UK number one hit for eight years after his song Candy topped the official singles chart.Read the full story ›
Robbie Williams is celebrating his first solo UK number one hit for eight years after his song 'Candy' topped the official singles chart.
The track, co-wrote with bandmate Gary Barlow, is the 14th number one of Williams' career - including Take That.
The Official Charts Company said it was the fastest-selling single by a male artist this year.
Take That star Robbie Williams and wife Ayda Field have announced the birth of their baby girl Theodora Rose Williams.Read the full story ›
Praise be, it's Theodora Rose Williams, affectionately known as Teddy. Born 3.33pm on 18.9.12, 7Ibs 4OZ.
Baby, Mummy and Daddy are all rockin'. Thank you for your best wishes XXXX.