Walter Cronkite, who has for months publicly opposed the Cape Wind project being proposed for Nantucket Sound, yesterday announced he has reconsidered - and his commercials on the subject will be withdrawn from the airwaves. Mr. Cronkite said he now prefers to be a more objective observer of both the process and project.

Opposition to this project, he said, "may be premature."

The former television newsman, in residence this summer at his longtime Edgartown home, said he will now await the outcome of ongoing studies before reaching a personal decision on the project. When he first lined up with the opposition, he said, "I did not realize ... that almost a score of government agencies were investigating and were preparing a report on the impact of the Nantucket Sound project. My final decision on the necessity of it being located in the Sound will await that report and the results of other investigations to determine whether the Sound is the only feasible location for a wind farm in this area." (Mr. Cronkite's complete statement appears on Page Fifteen this morning.)

Mark Rodgers, a spokesman for Cape Wind, said Jim Gordon, president of Cape Wind, met on the Vineyard with Mr. Cronkite on Monday to talk about the merits of the project. Mr. Rodgers said it was a lengthy meeting. While it may not have swung Mr. Cronkite's opinion of the project, it did cause him to decide he should be more objective, Mr. Rodgers said. After that meeting, Mr. Cronkite requested his voice and views not be used in advertisements to oppose the project.

Ernie Corrigan, a spokesman for the Alliance to Protect Nantucket Sound in Hyannis, said his organization will pull the Cronkite advertisements. "We respect that Walter Cronkite is taking more of a journalist's detached view of this project. As a journalist, he wants to gather more facts and does not want to be so publicly identified with the opposition. Our position, while we respect that, is that we have an ongoing problem with the process."

Another 60-second radio spot voicing opposition to Cape Wind's plan and now airing, features a year-round Vineyarder, author David McCullough. Mr. McCullough could not be reached for immediate comment.

As recently as last Friday, Mr. Cronkite in a syndicated newspaper column wrote: "Since I won't like the looks of that vast field of towers; and I won't like their interference with glorious sailing in the sound; and I will worry about the wildlife, including porpoises and whales on their visits and several birds of endangered species on their annual migrations; and I sympathize with the already severely ailing fishing industry, whose important resource those waters are - for these reasons I am opposed to the project."

But he also said at that time: "At least I am opposed until the developers can assure me that the sound is the only feasible site for these generators and that the location in the comparatively shallow and placid sound's waters is not primarily because the site would keep their costs lower and their profits higher than some offshore site."

In a statement from Cape Wind yesterday, Mr. Gordon acknowledged Mr. Cronkite's decision to reconsider. "Cape Wind appreciates that Walter Cronkite is now reassessing the merits of the wind farm proposal. We ask Cape and Islands residents to keep an open mind until the 17 federal and state agencies reviewing the project report their findings," he said.