ATLANTA — UPS Inc., the world's largest shipping carrier, said yesterday it is seeking more job cuts on top of 1,200 positions in its logistics unit it previously said it would cut.

The Atlanta-based company has offered voluntary severance packages to roughly 650 employees at its headquarters and in its Supply Chain Solutions division in the United States.

Those receiving the offers are at least 50 years old and have at least 10 years of experience, spokesman Norman Black said.

The company did not disclose a goal of how many people it hoped would take the severance offers, and Black declined to say whether there would be any forced layoffs if not enough people take the offers.

The personal election period ends Jan. 29. The company said it will discuss any significant financial impact from the cuts during a fourth-quarter earnings call with analysts the next day.

The cuts are in addition to the 1,200 jobs UPS announced in October that it would shed in its Supply Chain Solutions business, which handles air freight and logistics services.

At an investor conference last month, Chief Financial Officer Scott Davis told analysts there might be more cuts as the company evaluated the best way to deliver nonoperating functions such as human resources, finance and accounting, engineering and network planning.

UPS has been undergoing a restructuring meant to reduce costs and align transportation services and planning across the company.

Chief Executive Mike Eskew said at the investor conference that the company is confident its growth strategy is working amid competitive and economic challenges, but it must improve the performance of its logistics business, adding, "We know that we have to execute better than we have."