Mr Pain will leave the house builder on 30 June, at the end of the company's financial year.
In a trading update this morning Barratt said it had reduced debt by £230 million, but was warning of further landbank writedowns.
Barratt's chairman, Bob Lawson, said: “We are sorry that Mark has decided to leave the company and on behalf of the board I would like to thank him for the outstanding contribution he has made to the business, particularly during what has become an intensely difficult market.”
Mark Pain said: “After more than 10 years on company boards as an executive director, I have decided to pursue a wider portfolio of business and personal interests, including additional non executive roles.
“We have put in place new banking covenants and with our debt falling the company is now significantly better placed.
“I want to wish Mark Clare and the Barratt team every success in the future.”
A recruitment process for a new group finance director is underway and an announcement will be made once the process has been concluded.