Paul Myners is to step down from his role at the The London School of Economics after little more than a year, after having grown frustrated in the role.

Lord Myners’ colleagues say the crossbench peer is standing down because he was “impatient” with the slow pace of reforms to the LSE’s management and funding structures.

He is resigning as chairman of the LSE’s council and court of governors, but will stay on as a governor. He began work at the LSE in February last year.

The LSE said he was stepping down for “personal reasons” and that he had recently completed a review of governance for the university. Most of Lord Myners’ recommendations had been adopted, the LSE added.

But Lord Myners was said to be “frustrated by his inability to drive a modernisation agenda” and that his departure was less about the substance of the proposed reforms but more about the speed with which they were being delivered.

Lord Myners was always seen as more comfortable in the boardroom than operating within the constraints of the public sector.

The former Marks and Spencer chairman was hired by Gordon Brown as a City minister in 2008 and was valued for his connections with the City during the financial crisis.

During his time at the Treasury, he was known for his impatience and for losing interest “when he got the sense that others were not as committed to getting things done” as he was, according to one person who worked with him then.

One reason for Lord Myners’ appointment to the LSE had been his reputation as a money man and fixer: he led the review of governance at the Co-operative Group after its bank made a string of disastrous decisions and instrumental in the government rescue of RBS and Lloyds.

In an interview with the Financial Times published in January, Lord Myners said he wanted to multiply the LSE’s £113m endowment fund to £1bn because the college was living “hand to mouth.” The LSE on Thursday said there “was never a figure” for the endowment fund and that Lord Myners’ words reflected “an ambition”.

Lord Myners said he found the work very fulfilling and that he found interacting with students on campus “very satisfying”. He combined his posts at the LSE with a number financial roles — including positions at RIT Capital Partners, Autonomous Research and Cevian Capital — and at Edelman, the PR firm.