Boston Private Bank & Trust has filed suit against a former executive alleging he stole confidential information before starting work at a competitor, reports the Boston Herald.

The bank says former lending executive Todd Rassiger stole proprietary information that benefits his new employer, First Republic Bank.

Rassiger, employed by Boston Private for more than seven years until his resignation in February, allegedly attached personal USB flash drives to his work computer and downloaded more than 1,500 documents. He was, according to the complaint, a “leader” in lending to non-profit-making organizations.

The filing said: “The documents selected for downloading pertain to every critical aspect of the bank’s business, especially its commercial lending business, and are sufficiently detailed to enable Rassiger to effectively compete against the bank without having to expend many of the significant resources necessary to develop essential information contained in those documents... The documents comprise the building blocks necessary for Rassiger to assist another bank in establishing a non-profit presence and building its private equity and venture capital portfolio within its commercial lending business in the Boston market.”

Boston Private wants a court order restraining Rassiger from using the documents or disclosing them to a third party, plus unspecified damages.