Michael Jackson's doctor filed court papers on Friday indicating he plans to appeal his involuntary manslaughter conviction over the singer's death and his four-year jail sentence.

Lawyers for Dr. Conrad Murray filed the papers with Los Angeles Superior Court in a precursor to a formal appeal being lodged with a California Appeals Court.

Murray was convicted last month of involuntary manslaughter, or gross negligence, after admitting he gave the pop star nightly doses of the anesthetic propofol in June 2009 to help him sleep.

Murray was sentenced on Tuesday to four years in jail by an angry Los Angeles judge who called him a disgrace to the medical profession.

Jackson, 50, died in Los Angeles on June 25, 2009, of an overdose of propofol - which is normally used to sedate patients during surgery - and sedatives. His death came just weeks before a planned series of comeback concerts in London.