(WSJ) - Robert M. Parker Jr., widely regarded as the world's most powerful wine critic, has some far-reaching changes planned for his 34-year-old newsletter, the Wine Advocate. Mr. Parker intends to phase out the print version of the newsletter, which he built over the past several decades into one of the most influential voices on wine. He also said he intends to step down as its editor in chief, turning over editorial oversight to his Singapore-based correspondent, Lisa Perrotti-Brown. Finally, the fiercely independent publication—which Mr. Parker has often described as inspired by his hero, consumer advocate Ralph Nader—will start accepting advertising, though none that is wine-related.