The Indianapolis Metropolitan Development Commission gave final approval Wednesday afternoon for tax abatements that will help Celadon Group Inc. build a $3.4 million, 36,000-square-foot office building at its far-east-side headquarters.

The expansion should enable Celadon to retain 657 local employees at an average hourly wage of $19.76 and hire 100 more at an average hourly wage of $17 by 2016, the trucking firm said.

In addition, Celadon plans to invest $960,000 in new equipment.

The five-year property-tax abatements could save the company $261,308 during the term of the incentives. The investment should add more than $2.7 million to Indianapolis’ tax base, the city said.

Celadon occupies about 40 acres near East 33rd Street and Post Road. Founded in 1986, it has about 3,500 employees and 1,700 customers. Operating primarily under the Celadon Trucking banner, its fleet of 2,800 tractors and 8,200 trailers carry cargo in the United States, Canada and Mexico.