Covance Inc. is seeking state and local tax incentives as part of a $150 million expansion that would create 465 jobs at its Greenfield operations, nearly doubling the number of employees at the location.

The proposed expansion would occur over the next four years and include the construction of a new laboratory, the renovation of existing buildings and improvements to infrastructure, according to the Daily Reporter in Greenfield.

Princeton, N.J.-based Covance, a pharmaceutical research company, acquired the Greenfield Labs from Eli Lilly and Co. in October 2008 for $50 million and a 10-year agreement from Lilly to use Covance’s services. At that time, 264 Lilly employees shifted to Covance. The company currently employs 565 workers at the site, according to the newspaper.

The Hancock County Council is set to hear Covance’s request for incentives July 11.

Documents filed with the county show the 465 jobs would add $29 million in salaries with annual pay averaging more than $62,000 per employee, the Daily Reporter said.

Covance is expected to hire for administrative and laboratory positions.

The company uses the Greenfield Laboratories to conduct early-stage tests of experimental drug molecules, readying them for tests in humans.