ATHENS, Greece (AP) _ An Austrian tourist died and her husband was missing after a chartered yacht collided Saturday with a freighter and sank in the Aegean Sea, an official said.

It was unclear what caused the accident off Cape Sounion, 45 miles southeast of Athens, said a spokesman for the Merchant Marine Ministry.

The dead woman was identified as Susanne Sagl, 57, and her husband as Hubert Sagl, 59, the ministry spokesman said on condition of anonymity. No information was available about the couple's hometown, he said.

''We have launched a full-scale search operation by air and sea but there are no signs of the man so far,'' the spokesman said.

A passing cruise ship ferried the injured to Lavrion, a port near the site of the collision, and the remaining passengers and crew arrived later aboard the Anastassia K., an official at a Lavrion hospital said.

The cause of Mrs. Sagl's death was not immediately clear, the official said on condition of anonymity. He said it appeared the yacht's mast might have struck her as the boat keeled over.

The couple was traveling aboard the Greek Aghena yacht, which was carrying a crew of four and 20 West German and three Austrian tourists.

Two other passengers were slightly injured when the yacht collided with the Anastassia K. freighter, the spokesman said. It was not clear how many crew members were aboard the freighter, but all were reported safe, he said.

The Aghena had left Piraeus, near Athens, and was heading for the central Aegean island of Seriphos, part of the Kyklades island chain.

The Anastassia K. was heading for Piraeus from the southeastern Aegean island of Rhodes, charting a course contrary to that of the yacht, the ministry spokesman said.