Another sign of how difficult things have become in the global mining sector comes from Oak Creek, WI where Caterpillar Inc. announced that it is closing its mining equipment headquarters and moving the 250 administrative jobs there to its campus in South Milwaukee.

The Milwaukee Journal Sentinel reported that Caterpillar says it is taking the action as part of corporate-wide cost reduction efforts announced in September.

The Oak Creek offices, were the corporate headquarters for Midwest Airlines for 14 years. In 2010, the former airline sold the two office buildings — totaling 120,833 square feet on about 27 acres — to mining equipment-maker Bucyrus International. Bucyrus was acquired by Caterpillar, the world's largest manufacturer of construction equipment, for $8.8 billion in 2011.

Since then, the mining industry has fallen into a deep slump. Caterpillar, and Milwaukee-based competitor Joy Global Inc., have laid off hundreds of people in the Milwaukee area.

Now, Caterpillar says it will sell the Oak Creek offices and move everyone from there to South Milwaukee, where it manufactures mining equipment and has offices.

The consolidation will begin late this year and will be completed by the third quarter of 2016, according to the company.