Invesco Perpetual said that after 25 years with the company Mr Woodford had decided to leave to establish his own business.
He will remain responsible for all funds for which he is the named manager through a transition period during the six months prior to his departure. At the end of the transition, Mark Barnett will be named manager of the Invesco Perpetual High Income Fund and the Invesco Perpetual Income Fund. He will then succeed Neil as Head of UK Equities.
With immediate effect, the UK equity components of the Invesco Perpetual Monthly Income Plus Fund and the Invesco Perpetual Distribution Fund will be managed by Ciaran Mallon alongside the existing fixed income managers Paul Causer and Paul Read.
Mark Armour, chief executive of Invesco Perpetual, said: "Neil has served clients of Invesco Perpetual with commitment for over 25 years. It has been a privilege for us all to work alongside him, and I understand that, after 25 years, he is ready for new challenges."
He added: "We have planned for succession for many years and have built a world-class investment culture that develops and supports gifted and experienced managers. Mark Barnett is an exceptional fund manager who has the same active, value-driven investment approach and long-term focus as Neil. A key member of the UK Equities team for 17 years, Mark has a first-quartile track record over one, three and five years.
{desktop}{/desktop}{mobile}{/mobile}
"We are confident that Mark, Ciaran and the UK Equities team will continue to do an excellent job for clients."
Mr Woodford said: "I leave the company on good terms and remain fully committed to my fund management responsibilities at Invesco Perpetual until my departure. The Invesco Perpetual High Income Fund, Invesco Perpetual Income Fund and other client mandates will be transitioned into the hands of my long-standing, experienced colleagues. I wish my colleagues all the best for the future."
He continued: "My decision to leave is a personal one based on my views about where I see long-term opportunities in the fund management industry. My intention is to establish a new fund management business serving institutional and retail clients as soon as possible after 29 April 2014. There will be no further comment at this stage. Further announcements about the new business will be made after I have left."
Mark Dampier, head of research at Hargreaves Lansdown, said: "Neil Woodford has over 25 years managing money at Invesco Perpetual and I believe he will continue to work hard at achieving strong performance for investors until he departs in April. We believe investors need not consider selling the fund now and I myself will be remaining invested.
"For new investors we would however suggest waiting until the new manager has taken over the fund and have suspended it from the Wealth 150 for the time being."
Ken Rayner, of investment ratings company Rayner Spencer Mills, said: "The news from Invesco of the impending departure of Neil Woodford clearly raises a number of concerns for investors. We have some time before he leaves and so will review the changes in full before making any decisions on ratings and portfolios.
"The new managers are experienced and both have excellent records within the Invesco UK equity team and we will have the opportunity to meet with them in the near future. The funds will continue to retain their rating until we have had the opportunity to review the situation in full."
Invesco Perpetual manages more than £70bn across a wide range of asset classes for clients in the UK and across the globe.