Horizon Lines Inc. announced a non-union workforce restructuring initiative targeted at reducing annualized labor-related costs by an estimated $7 million to $10 million.

The company, which is the second largest shipping company serving Hawaii, said it intends to reduce its workforce by at least 10 percent, or approximately 70 of its 700-plus non-union employees.

The company said it initially will offer a voluntary severance program to certain eligible non-union employees. If the company is unable to achieve anticipated reductions from the voluntary program, it intends to implement an involuntary severance program for non-union employees.

Horizon said it expects to complete the workforce reduction initiative by January 31, 2009, and it is expected to result in a fourth-quarter 2008 charge of approximately $3.5 million to $5 million pretax, or 11 cents to 16 cents per fully diluted share.