By Dan Williams

JERUSALEM (Reuters) - Former Prime Minister Ehud Olmert said on Thursday he had no plan to return to Israeli politics after a court cleared him of major corruption charges that prompted his resignation in 2008.

Israeli media had speculated that Olmert might ally himself with the opposition, now that his centrist Kadima party has a new leader and forms part of the conservative coalition government of Prime Minister Benjamin Netanyahu.

The career politician had pursued vigorous peacemaking with the Palestinians, now long stalled. But a slew of police investigations, as well as his conduct of the costly 2006 Lebanon war, plunged his approval ratings to single figures.

"I want to calm all those who are worrying. I have no intention of getting into political activity. I am not involved and do not intend to become involved," Olmert, 66, told the Institute for National Security Studies, an Israeli think-tank, at a conference marking the sixth anniversary of the conflict.

"I have a party, Kadima, to which I belong. I have no contingency party, nor will I have such a party," he said, looking drawn but defiant. "And now I am busy with other things, and only them."

Though acquitted by a Jerusalem court on Tuesday of bribery and fraud, Olmert was convicted on a lesser charge of breach of trust for cronyism while serving earlier as trade and industry minister.

He awaits sentencing on that count, as well as a verdict in a separate bribery case over his role, as Jerusalem's mayor from 1993 to 2003, in the building of the huge Holyland housing complex, widely considered to be the city's biggest eyesore.

Olmert has denied any wrongdoing and Tuesday's ruling prompted a wave of Israeli soul-searching about his resignation and trial, which coincided with treatment for prostate cancer.

But a Channel 10 television survey whose results were aired on Wednesday found that 70 percent of the public would oppose him re-entering politics, with only 22 percent in support.

Olmert spokesman Jacob Galanti said the ex-premier "won't return to political life as long as there is a cloud over him".

At the INSS, Olmert gave a spirited defense of the 2006 war, during which outgunned Hezbollah guerrillas fought Israel's forces to a standstill while their cross-border rocket salvoes sent a million Israelis to bomb shelters.

During 34 days of fighting 1,200 people were killed in Lebanon, mostly Lebanese civilians, along with 158 Israelis, mostly soldiers.

"It brought about a deterrence that had never previously existed on the Lebanese border," Olmert said.

Olmert, whose aides have long accused Netanyahu's camp of fanning popular anger against him, accused "members of the media and certain political interest groups of portraying the State of Israel as having lost that war".

(Writing by Dan Williams; editing by Tim Pearce)