Westfield increased its service charges from an annual cost of£8.50 per sq ft (£78.95 per sq m), to about£14 per sq ft (£130 per sq m).
According to the Financial Times, Next will only pay the original guide price.
Next group property director Andrew Varley said: “Next is not happy with the level of service charges at Westfield, which it views as unreasonable. We are in discussions with the landlord along with other major retailers at the centre and hope to resolve the matter amicably.”
Westfield said the service charge is still “under review as the centre is still in its first year of trading”.
Last month Retail Week revealed WHSmith and Fred Perry were among retailers to have appointed consultancy firms to investigate service charges on their behalf.