GENEVA, SEPT. 21 -- Licio Gelli, former grand master of Italy's mysterious P2 Masonic lodge, turned himself in to Swiss police today, four years after having escaped from a maximum-security prison here.

Gelli, 68, is accused in his native Italy of being involved in a series of criminal and financial scandals that brought down the country's government in 1982 and also provoked the collapse of the Banco Ambrosiano, a bank with which the Vatican was closely involved. He surrendered to Judge Jean-Pierre Tremblay as part of a deal worked out Friday.

The financier faces a maximum jail term of 4 1/2 years for having bribed a jail guard to let him escape Aug. 10, 1983. Since that date he has been a fugitive, reportedly in Latin America, where he has business connections.

Through a lawyer, Gelli said he wanted to clear his name "because I do not want to spend the rest of my days as a fugitive in exile." He said he was ready to be extradited to Italy if necessary, where he faces more serious charges of bribery, corruption and extortion involving the secret lodge.

In 1982, Italian authorities said the lodge had 900 members, including four Cabinet ministers, top echelons of the Italian secret service, several generals and disgraced former banker Michele Sindona.

The authorities said the lodge was involved in a coordinated effort to manipulate Italian politics and business for its own ends. The scandal brought down the government of the time. Gelli fled to Switzerland, where he was arrested Sept. 13, 1982, for using a false Uruguayan passport while trying to withdraw money from a numbered account in Geneva.

Less than a year later, as Gelli faced extradition to Italy, he was "sprung" by a prison guard of Italian extraction who admitted at his own trial that he was bribed by Gelli.

After surrendering to Tremblay, Gelli was hospitalized under heavy police guard, reportedly suffering from a heart condition. Tremblay said that if Gelli's health permits he could appear before a Swiss court before the end of the year.

"The main question that arises is, is Gelli prepared to sing?" said Italian legislator Massimo Teodori, a member of a commission that investigated the P2 affair five years ago. In an interview with Swiss TV, Teodori added, "He knows where the bodies are buried and if he starts talking in Italy there are going to be a whole new series of revelations."

The judge said Italian authorities must make a new extradition request on charges they may wish to bring against him.

Alleged members of Gelli's P2 lodge also have been charged with criminal activity in Argentina during the Peronist and military governments there in the 1970s. Gelli was appointed in 1974 by president Isabel Peron as Argentina's commercial attache in Rome.