* Lawyer says "good probability" Berlusconi will request pardon
* President Napolitano has not ruled that out
* Napolitano puts government survival above all else
By Barry Moody
ROME, Aug 14 (Reuters) - Silvio Berlusconi is likely to request an official pardon for a tax fraud conviction, his lawyer said on Wednesday, after President Giorgio Napolitano warned his party to stop its threats to bring down Italy's government over the sentence.
Napolitano issued a long-awaited statement on Tuesday night on Berlusconi's definitive conviction by the supreme court on Aug. 1 which risked tearing the fractious left-right coalition government apart.
Italy's papers were filled with pages of interpretation of Napolitano's long and complex statement in which he said the law must take its course, but did not rule out an eventual presidential pardon for Berlusconi, under strict conditions.
Franco Coppi, the lawyer who defended the media tycoon, was asked about applying for a pardon in an interview with the Affaritaliani.it website. "At the moment there is a good probability, although nothing has yet been decided," he replied.
The most important part of Napolitano's statement was his adamant defence of the government of Prime Minister Enrico Letta, which he forced into existence in April after a two-month crisis following inconclusive February elections. He rejected threats by Berlusconi supporters to force a new poll.
The government is a coalition between the 76-year-old Berlusconi's centre-right People of Freedom (PDL) and Letta's centre-left Democratic Party (PD).
The head of state said a government crisis just as Italy is seeing the first tentative signs of recovery from its worst postwar recession would be "fatal" and angrily dismissed demands from PDL hawks that he find a way to circumvent the law and prevent any limitation of Berlusconi's political activity.
The supreme court confirmed a four-year jail sentence - commuted to one year - on Berlusconi for a giant fraud at his Mediaset television empire. The Senate will meet in the autumn to decide whether to remove the four-times prime minister from parliament and prevent him standing for election.
Berlusconi is not expected to go to jail because of his age but would serve the sentence either under house arrest or doing community service. A supervising judge will decide the restrictions on his political activities.
Napolitano said he understood the consternation in the PDL over the conviction of their party leader - Berlusconi's first definitive sentence in around 30 trials since he entered politics in 1994.
The president said Berlusconi was the uncontested leader of an important political force but this did not excuse attempts to challenge the division of powers between judiciary and legislature and the independence of the judges.
His remarks were widely interpreted as indicating Berlusconi could hope for an eventual pardon but only if he accepted his sentence, began serving it and stopped his constant attacks on what he calls leftist magistrates bent on undemocratically removing him from politics.
The leftwing newspaper il Fatto Quotidiano ran a banner headline reading: "I will pardon you if you are a good boy."
PDL leaders and some commentators suggested Napolitano's emphasis on keeping the government afloat in the national interest was a warning to Letta's PD not to vote for Berlusconi's ejection from the Senate, which is the most likely spark for a government crisis in the autumn.
PDL former Education Minister Mariastella Gelmini said the survival of the government now depended on the PD's ability to "marginalise its anti-Berlusconi impulses and put the country's interests before its hatred for the enemy."
The centre left is itself riven by factional fighting and a large group on its left wing is already deeply uneasy about being in a governing alliance with Berlusconi.
It is thought unlikely that the party could vote in favour of the media magnate staying in the Senate, especially since it is under pressure from the populist 5-Star Movement of comedian Beppe Grillo, which said on Tuesday Napolitano should be impeached if he pardoned Berlusconi. (Additional reporting by Steve Scherer and Roberto Landucci; Editing by Robin Pomeroy)