By Alexander Tanas

CHISINAU (Reuters) - Former Moldovan prime minister Vlad Filat was sentenced on Monday to nine years in prison for abuse of power, a charge his lawyer said was a politically motivated attempt to humiliate him.

Filat was arrested during a parliamentary session last October after months of mass street protests over the disappearance of $1 billion from the banking sector, equivalent to one-eighth of the tiny ex-Soviet republic's economy. He denies any connection to the crime and all charges against him.

Prosecutor Adriana Betisor, who had sought a sentence of 19 years, said the ruling, at the end of a closed trial, was "too soft", and vowed to continue pursuing other cases against Filat connected to the banking fraud.

"He has pleaded not guilty, but his guilt is clear ... Investigations will continue in other areas," Betisor said.

Filat's lawyer, Igor Popa, called the case "a political, well-directed spectacle."

"Its goal was to destroy Filat as a person, in the most humiliating and crushing manner possible. We will seek a fair trial outside Moldova and will find a lawful ruling," he said.

Filat, who served as prime minister from 2009 to 2013, is credited with putting Moldova on a pro-European path by signing an association agreement with the European Union. But an enduring economic crisis and perceived corruption in the ruling elite pushed his public trust rating into single digits.

He says he has become a scapegoat over the banking scandal, which weakened Moldova's currency and damaged living standards in what was already Europe's poorest country.

The crisis has held up the disbursement of valuable budget support from international lenders and highlighted the corrosive rivalry between oligarch groups in Moldova.

The appointment of a new prime minister in January with close ties to Vladimir Plahotniuc, one of Moldova's richest and most unpopular public figures, angered opposition lawmakers and citizens, who wanted a snap parliamentary election.

(Writing by Alexei Kalmykov and Alessandra Prentice; Editing by Mark Trevelyan)