BT said last month that sales dropped 1% in the year ended March 31, while profits dropped 2%. The broader reaction to our recent results announcement has, though, demonstrated to Gavin and me that there is a need for a change of leadership to deliver this.
Patterson stepped up to the top job in 2013, replacing Ian Livingston who joined the House of Lords, having been appointed as the managing director of BT Consumer back in 2004 and appointed to the board in 2008.
Patterson said he was "immensely proud" of what had been achieved at the former telecoms monopoly, including a multi-billion pound move into sports broadcasting, buying Britain's biggest mobile operator EE and a hard-won agreement to create greater independence for its networks business Openreach.
He will step down when a successor is in place, likely in the second half, BT said in a statement yesterday.
The search for Patterson's successor is now underway, the company added.
In January last year, BT wrote down the value of its Italian unit by £530m after it said it had uncovered years of "inappropriate behaviour".
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So I am just focusing on what is ahead, and I am confident that I can turn things around. It could have been better but everybody makes it so dramatic'.
BT shares plummeted after it was announced, and are now trading near a six-year low.
Patterson's leave follows major restructuring at BT.
Mr Patterson will stay in his role until that time.
"I am confident that, for the remainder of his term, Gavin and his senior management team will continue to display the energy required to deal with every dimension of the task at hand", he said.
He managed to avoid a full break-up of the group by agreeing to legally separate Openreach, but he admitted he had been taken aback by the flak BT had received about its customer service and its networks during the bitter two-year battle.
Mr Patterson has been seeking to reboot BT since a profit warning early past year, and told investors last month that it will take until 2021 for a return to profit growth as the company reorganises.