Salt Lake County commissioners have approved payment of an additional $39,000 to a consulting firm that has a $183,000 contract to assist with a feasibility study of a proposed new downtown arena.

The Murray office of Phoenix-based DMJM was selected in August for the project over four rival bidders. The architectural and engineering consulting firm has since provided technical support to a citizens task force appointed by county commissioners to explore options for a new arena. The arena is estimated to cost $75 million to build.However, the DMJM contract ran only through Oct. 31 - the original deadline commissioners gave the task force to submit a feasibility report. Commissioners later extended the task-force deadline. Because DMJM has continued assisting the task force, the consultant's contract will be extended through Dec. 31.

Commissioners have approved payment of another $25,000 to DMJM for the additional time consultants will spend working on the project. Another $14,000 payment was approved for compilation of local population demographics information, including an opinion poll on the new arena proposal.

In June commissioners appropriated $300,000 for the arena study. No final date has been set for submission of the feasibility report.