Former HIH director Dominic Fodera's current two-year jail stint has been increased by at least 12 months for his latest offence.
In the NSW Supreme Court on Tuesday, Justice Virginia Bell found the offence was "knowingly dishonest", rather than reckless, and concluded Fodera lacked remorse for his crime.
She set a minimum 18-month term, which will overlap with six months of his current two-year term, meaning he will serve a total of at least three years behind bars.
He had pleaded guilty to failing to act honestly in the discharge of his duties of office, doing so dishonestly and intending to gain beneficial accounting treatment for HIH.
Earlier this year, he received his first jail term after a jury found the 48-year-old married father of four guilty of authorising a prospectus from which there was a material omission.
Fodera was the chief financial officer and executive director of HIH, which collapsed in March 2001 with debts of $5.3 billion.
Justice Bell said the latest offence involved Fodera failing to inform HIH's directors and auditor of the true terms and effect of certain matters in relation to reinsurance contracts, over a two-month period in 1999.
They involved "understandings and arrangements that had been negotiated between HIH and its subsidiaries and the Hannover group of companies".
In rejecting a submission that Fodera's actions had been "reckless", the judge said the only rational inference to be drawn was that he had been "knowingly dishonest".
She noted he was a committed Christian, and a loving and responsible father and husband.
But the evidence by three clergymen had not persuaded her of Fodera's contrition for his offence, as distinct from his sincere regret over the collapse of HIH and the associated loss to many people.
Describing the offence as serious, Justice Bell said Fodera held a very senior position in HIH, a large public company.
His deliberate breach of his responsibilities had been a "serious breach of trust", but she acknowledged it was not said to be related to the collapse of HIH.
The earliest he will be eligible for release on parole is May 2010, while his total sentence will expire in March 2012.