Samaranch was taken to hospital on Tuesday night, his 81st birthday, but an IOC spokeswoman said there had been no change in his condition since late Wednesday.

But she did confirm the Spaniard was doing well, but could give no further details.

Samaranch is expected to stay in hospital for several more days and will not attend Friday's ceremony in Lausanne when Belgian Jacques Rogge will officially take over as the organisation's President.

Samaranch ended his 21-year term as IOC president on Monday when Rogge was elected to replace him at the IOC's meeting in Moscow.

Samaranch's problems began when he returned to Switzerland on Tuesday evening, arriving in Geneva at 1845 BST following a three-hour flight from Moscow and then travelled on to Lausanne, where the IOC is based.

"He didn't feel good last night and went to hospital but he is feeling better today," an IOC spokesman said. "The doctors want to keep him in for a day or two."

The Spaniard was very emotional on Monday as he handed over power to Rogge. He attended a meeting on Tuesday morning before flying back to Switzerland.

IOC director-general Francois Carrard told the Reuters news agency that Samaranch suffered breathing difficulties later that night.

"He flew with us last night very normally. He was in great condition and he even went into the cockpit for the landing.

Lavish ceremony

"He then went on with Olympics interviews post-midnight. How anybody over the age of 40 could handle that I don't know.

"Then he had respiratory difficulties which he has had before. He needs to stay quiet for a few days. He is much better now and I plan to pay him a visit later on today."

IOC vice-president Kevan Gosper said at the IOC headquarters in Lausanne on Wednesday that the situation of Samaranch had improved.

"He is better today but his doctors have required that he remains quiet and we will respect that."

Downscale ceremony

"He is a very strong man and he recovers very quickly and we are optimistic."

Samaranch is due to hand over the keys to IOC headquarters on Friday in a lavish ceremony but the event will now be reduced in scale or even cancelled.

"There are plans for it to be more of an internal affair and downscale the ceremony," the IOC spokesman said.

Carrard added: "We will take a decision tonight and we're keeping the options open."

Samaranch is now the organisation's life president and will continue his role as head of the foundation that looks after the Olympic museum, which is to be renamed the Samaranch Olympic Museum.