EE could be set to offer faster mobile broadband speeds via its 4G network, using LTE-Advanced (LTE-A) technology.
Tests conducted by the operator - in conjunction with Qualcomm Technologies and Huawei - have delivered peak download speeds of 410Mb.
These are significantly faster than the 300Mb variant of LTE-A being rolled out in parts of London, which deliver average speeds of around 90Mb.
The speed improvements are largely due to LTE-A’s new Carrier Aggregation mode, which allows operators to combine radio spectrum to effectively double its capacity.
Tom Bennett, Director of Network Services at EE, said working closely with the "excellent teams" at Qualcomm and Huawei on next-generation LTE Category 9 connectivity enables the firm to make full use of its spectrum holdings.
He claimed that EE will continue to offer world-class network capabilities, innovating to stay one step ahead of operators in Europe.
"Use of our remaining 15MHz of 2.6GHz spectrum enables both our fastest speeds and an increase in capacity across our network and this successful testing phase is a big step forward," Mr Bennett added.