Boston-based Liberty Mutual Group has completed its purchase of Argus Insurance Co. Ltd. captive management subsidiary. The sale of Argus International Management Ltd. was completed last week.

Argus chief executive officer John Sainsbury said Liberty had bought about 80 percent of the subsidiary, which has a staff of seven headed by Michael Hardy.

A Liberty Mutual spokesman said the company had no comment to make about the purchase at this time. The company has applied to incorporate Liberty International Management (Bermuda) Ltd. It was unclear what Liberty intended to do with the subsidiary.

Mr. Sainsbury had previously stated: "Liberty International has an aggressive expansion policy. They are moving into South America and Mexico and are keen to include Bermuda...They (the group) eventually hope Bermuda would become a financial hub of Liberty International.'' Argus has had a 15-year relationship with Liberty, an international multi-line property and casualty insurer. Argus International manages Liberty Mutual Management, Liberty Mutual (Bermuda) Ltd., and its rent-a-captive operation Lexco Ltd.

In a joint venture with Liberty and other companies, Argus also owns Stuart Insurance Group Ltd., a non-controlled foreign corporation. Argus International is profitable and currently manages 35 companies.

Liberty has about $40 billion in consolidated assets, and $50 billion under management. The company ranks 126th among Fortune 500 companies.