"I see the government as stable and focused on its goals and I don't foresee any impact of any kind on the government's determination, including from ongoing court cases," Letta told foreign reporters.
"I don't see any risk of early elections in the short term, I don't think we're at this kind of juncture," he added.
The constitutional court on Wednesday rejected a bid by Berlusconi to invalidate a tax-fraud conviction which observers have warned could force him out of politics altogether.
An appeals court in May had upheld a one year prison sentence and a five-year ban from public office for the magnate.
The fraud case revolves around prices of film distribution rights bought by the media magnate's company Mediaset that were artificially inflated in order to avoid taxes.
An MP from Berlusconi's right-wing party had threatened a withdrawal from Letta's governing coalition should the veteran politician be forced to step down from the Senate, to which he was elected in February.
Italian newspapers however have argued that it was in Berlusconi's interest to keep the current coalition alive rather than risk bringing about another government in which his party is not a partner.
Opinion polls also suggest he would not benefit from early polls.