Chief of staff Howard Baker says his 18 months in the White House were a "real eye-opening experience" but he leaves with no regrets and no plans to write a book.

In a farewell interview Thursday, Baker told United Press International he would love to be president, but considers it highly unlikely Vice President George Bush will offer him the second spot on the Republican ticket in this fall's presidential election."I'd love to be president," Baker said. "I wouldn't be a politician if I didn't aspire to that, and I sure am a politician."

But Baker gave up his own fledgling campaign for the 1988 GOP presidential nomination to come to President Reagan's rescue as the Iran-Contra scandal mushroomed.

Baker, who served 18 years as a senator from Tennessee before deciding not to seek re-election in 1984, said he was not prepared for what he encountered at the White House. "It was a real eye-opening experience," he said. "Everything comes to the White House and damn near everything comes across" the chief of staff's desk.

Baker made it clear he will not follow the example of his predecessor, Donald Regan, and write a book about his White House experience.

Baker said he was happy to find out there was no trace of evidence to dispute Reagan's word that he did not know money had been diverted from his secret weapons sales to Tehran to aid the Nicaraguan Contra rebels in defiance of the law.

He had high praise for Reagan, declaring that he "has once again demonstrated that the presidency is a manageable human undertaking despite the conventional wisdom that it's too big for a mere mortal."

"I think Ronald Reagan does it with grace and style and I think he absolutely hates the 22nd Amendment," Baker added, referring to the constitutional bar against a president's running for a third term.

The job of top presidential aide, he said, is "demanding in the extreme. It's exciting. It's extraordinarily rewarding, but it is hard, hard, hard duty."

Looking back on his tenure, Baker said, "I'm happy to have had some part in it, and I'm happy to go home."