A Portland lawyer has had his law license suspended for three years after he was deemed unable to adequately serve his clients because of substance abuse.

David Hunt, who was admitted to the Maine Bar in 1981, agreed to the suspension imposed by the Maine Board of Overseers of the Bar. The suspension can be shortened by 18 months if he abides by conditions.

Hunt has worked for small firms or as a sole practitioner in the Portland area since 1997, but at least as early as December 2010, has had several hospitalizations for alcohol abuse.

Hunt’s practice was placed in receivership by the board in August 2011.

The board determined that he was unable to adequately manage his clients’ legal affairs and said his handling of clients’ trust accounts was not proper, in that he sometimes billed the accounts for services in advance of them being performed, the board’s findings said.

Hunt is in a Maine hospital receiving treatment for a physical malady, the board said. He told the board he has not had alcohol since he was hospitalized in July 2012.

The suspension is retroactive to August 2012, so he could be eligible to resume practice in seven months.