A French-based expedition to the RMS Titanic, which has been accused at times of exploiting the historic wreck, actually cleaned part of it up this week, a spokesman for the expedition announced yesterday.

Daniel Puget of the Paris-based Taurus International offshore operations firm said by phone from Paris that the crew of the three-man French mini-sub Nautile polished up the Titanic's nameplate during a five-hour dive to the wreck site Monday.

Working more than 2 1/2 miles beneath the surface of the North Atlantic, he said, the Nautile's crew used the sub's manipulator arms to pick chunks of red corrosion from the white-painted letters on the Titanic's port bow, then photographed and filmed the name for the world to see. Only the letter "A" remains illegible, he said.

Puget said the expedition does not intend to remove any pieces of the Titanic that are part of the hull, but did recover earlier this week a stained-glass window found unbroken in its frame on the floor of the restaurant aboard the ship. In New York, Walter Lord, author of "A Night to Remember" and de facto dean of Titanic scholars, said the window is probably an art deco panel that covered two portholes in the Titanic's luxurious main dining room.

"I'm astonished it remained unbroken all these years," he said.

The Titanic, in its day the largest and most elegant ship ever built, sank April 15, 1912, after hitting an iceberg on its maiden voyage from Southampton, England, to New York. More than 1,500 passengers and crew were lost in the sinking, which historians since have pictured as a metaphor for an age of elegance and optimism consumed two years later in World War I.

Puget said the expedition has located a gap in the wreck through which it hopes to maneuver a remote-controlled camera later this week to obtain pictures of a 1912 Renault auto that was purportedly being shipped home by John Jacob Astor, one of the Titanic's many wealthy passengers.

Lord, however, said shipping manifests indicate Astor brought no such auto aboard. "That car belonged to Billy Carter," he said, "a rather flamboyant Philadelphia socialite" later accused of donning a dress to win a place in one of the Titanic's few lifeboats with the women and children. "John Jacob Astor seems to get credit for almost everything on the Titanic," Lord said, wearily.