Gavin Patterson, BT CEO, is leaving after five years in the post.
A search for Patterson's successor has started and is expected to be in place by the second half of this year.
"The broader reaction to our recent results announcement has. demonstrated to Gavin and me that there is a need for a change of leadership to deliver this strategy", he said.
During his time at the helm, Patterson has overseen a number of changes in the business, not least its entrance into the TV market.
Patterson has been with the United Kingdom incumbent telco for 14 years, serving as a member of the Board for the last ten.
With its share price at a six-year low, the telecoms giant is looking to cut back its management positions and "consolidate in key towns" to reduce costs by £1.5 billion.
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.
BT shares, which have lost almost 40 percent of their value since Patterson took over, rose more than 2 percent in early trading, before giving up some of the gains by 1030 GMT.
Patterson's leave follows major restructuring at BT.
As part of a three-year plan aimed at reversing the firm's downward spiral and to save 1.5 billion pounds, BT planned cut 13,000 managerial and administrative jobs. The first and most important is the share price. He was appointed chief executive of the BT Group in 2013.
Analysts at UBS said the fact that the board supported the strategy suggested no significant strategic changes.
As well as its financial performance BT has been consistently criticised for its service level in broadband and overall customer service.