Found this on The Doctor Who News Page: Answering questions on his official website, Fourth Doctor Tom Baker has said that he has agreed to record a Big Finish Audio production.
Baker was answering a question asking what story he would do if he was given carte blanche to create any story he wanted. He replied that he has been in talks with Big Finish and that they have accepted some of his ideas. Baker recorded Hornets' Nest for BBC Audio last year, but has never worked for Big Finish before. Any project is likely to be in early stages of production and has not been confirmed by Big Finish.
Tom Baker is answering about 20 questions per month via his website. Questions need to be submitted via the forum on the website. Please read the guidelines before posting.