LONDON, NOV. 14 -- PepsiCo Inc. announced today that it was ending its nine-year, multimillion-dollar relationship with Michael Jackson in the wake of the pop star's cancellation of his world tour. Jackson, meanwhile, remained out of sight amid circumstantial indications -- inflated to near-certainty by London's excitable tabloid press -- that he might be somewhere in Britain.

Jackson, perhaps one of the half-dozen most recognizable people in the world, appeared to have vanished without a trace since an announcement Friday that the tour was off. It was no mean feat, given that no holds were being barred in the frenzied attempt to track him down. Reporters scoured the English countryside, staking out hotels and hospitals, and even Toys R Us branches and exotic zoos, in vain hopes of finding the elusive entertainer.

The British press finally settled on a swank private clinic in London as Jackson's most likely whereabouts. But in truth, by nightfall there was still no firm indication that he was inside. Jackson lawyer Bertram Fields scheduled a news conference Monday in Los Angeles.

The loss of the Pepsi contract appeared to be a severe setback for Jackson, who has been under pressure personally and professionally since August, when allegations by a 13-year-old boy that Jackson had molested him first came to light. No charges have been filed, but a criminal investigation is underway, and Los Angeles police have raided Jackson's homes. In addition, the boy has filed a civil suit seeking damages. Jackson strongly denies the allegations, calling them "an extortion attempt."

PepsiCo spokesman Gary Hemphill said today that the company's only agreement with Jackson was to sponsor this particular international tour. "The cancellation ... really effectively cancels our relationship with Michael right now," Hemphill said. "We just hope he is able to resolve his problems."

Jackson prompted what amounts to a worldwide manhunt on Friday when he announced, via a tape-recorded statement played for reporters in Mexico City, that he was canceling the remainder of his "Dangerous" world tour so he could seek treatment for an addiction to painkillers.

The pop star abandoned a tour in tumult. He had canceled a third of 30 shows since it began, blaming scheduling conflicts and various maladies. In the statement, Jackson, 35, said he had developed this chemical dependence partly because of stress caused by the allegations of child molestation.

Jackson reportedly boarded a chartered Boeing 727 Friday in Mexico City along with actress Elizabeth Taylor, a close friend, and a third person, supposedly Taylor's husband, Larry Fortensky. The plane made stops in Canada and Iceland before landing at Luton airport near here early Saturday. Then the plane took off again, heading for Geneva. It was assumed that Taylor, who has a chalet in nearby Gstaad, was taking Jackson to one of the private Swiss clinics that allow celebrities to dry out in total privacy. KNBC-TV in Los Angeles said Interpol contacted the Los Angeles Police Department on Friday to say Jackson was passing through customs in London, on his way to Switzerland.

But when the plane arrived in Switzerland, Jackson did not seem to be aboard. Taylor was, and she left the Geneva airport for an undisclosed destination, according to press reports. The British Broadcasting Corp. sent a reporter to Taylor's chalet, only to find it dark and apparently unoccupied.

Those "facts," all based on sightings and non-sightings of sunglasses-wearing people darting across tarmacs, led to the conclusion that Jackson must have left the plane at Luton and gone to some destination in England. "Jackson vanishes in Luton triangle," said a headline this morning in the Sunday Times.

According to the newspaper, a government spokesman confirmed that two people had left the airplane in Luton, but would not identify them.

By midday today, most attention was focused on the exclusive Charter Clinic in the Chelsea neighborhood of London. Officials of the clinic refused to confirm or deny that Jackson was there, saying it is company policy to make no comment about its clientele.

Though Jackson has insisted from the beginning that he is innocent of the molestation charges, the situation appeared to be taking its toll on him. A U.S. Embassy staff member in Mexico City said Jackson received a pro-forma invitation to visit the embassy shortly after arriving there on Oct. 24, but members of the singer's staff immediately expressed suspicion.

"His manager called us up and started asking lots of questions," the embassy employee said. "At first we thought they were trying to figure out logistics, but after a while it became clear what they were getting at: They thought we were setting a trap to arrest him and send him back to the United States."

The employee said the embassy had no such intention. "Talk about paranoia. Hell, we just thought everyone would get a kick out of meeting him," he said.

Jackson arrived in Mexico City several days earlier than expected after canceling concerts in Chile and Peru, and stayed in Mexico nearly three weeks -- far longer than originally expected. His sold-out, four-concert engagement had to be postponed when the singer reportedly underwent dental surgery.

He and his entourage holed up in the top four floors of a five-star Mexico City hotel, appearing in public only on two occasions: to pose for photos with President Carlos Salinas de Gortari and to visit a wildlife park where Keiko, the killer whale that starred in the movie "Free Willy," is being kept. Jackson recorded the soundtrack to the movie. But Jackson was pointedly shunned by Mexico City officials at the Nov. 6 opening of a gigantic new children's museum.

Before he announced the end of his tour, Jackson had already been barred from appearing at two November concerts in Dubai, one of the United Arab Emirates. The country barred Jackson from appearing there after unsigned pamphlets were circulated in Dubai urging a boycott of the concerts and of Pepsi-Cola. The emirate said its ban was "in line with the traditions, values, culture and habits of the Arab society in the U.A.E."

Little is known about the nature of the addiction that Jackson says he has acquired. He said in his statement that he had become dependent on unspecified painkillers that he began taking several months ago after surgery on his scalp. Jackson's scalp was burned in an accident during the filming of a Pepsi commercial years ago.

Jackson first signed an endorsement deal with Pepsi in 1984. It brought him $6 million -- at that time a record for celebrity endorsement. Since then Pepsi has sponsored three Jackson concert tours, paying him fees of $20 million; over the same period, Pepsi has reportedly picked up two market share points on arch-rival Coca-Cola -- worth about half a billion dollars in sales annually.

Staff writers Tod Robberson in Mexico City and Richard Harrington in Washington contributed to this report.