The final report of a citizens task force appointed by Salt Lake County commissioners to explore options for a larger downtown arena complex to house the Utah Jazz will be delayed about six weeks.

Commissioners had asked the task force when it was formed in July to deliver its report by Monday on the feasibility of developing a larger arena, expanded convention-hosting facilities and a new science center.But studying the proposal turned out to be a bigger job than anyone anticipated, said John W. Rosenthal, director of the county's administrative services department and task force executive director.

The 90 days allowed for the study wasn't enough time, and the task force has tentatively set Dec. 9 as its new target date for delivering a finished report to the commission, Rosenthal said.

"We wanted to make sure that if any expansion at all is recommended, that we leave no stone unturned to get all the information," he said. "We would rather be thorough and take a little longer to make sure we are right than to go too fast."

A preliminary report recommended that a new 18,500-seat arena be built for the Jazz, which will need additional revenue from ticket sales to support the team's payroll, expected to double under terms of a new NBA collective- bargaining agreement.

A preliminary estimate of the costs for the arena and convention facilities was put at $30 million to $60 million, but indications are the final price tag may be higher. Commissioners have pledged taxes will not be raised to build the complex.