Spokane County commissioners will sign a 10-year lease with the Spokane Indians for the baseball team to use Avista Stadium.

Longball Inc., a division of Brett Sports that manages the minor league team, will pay $15,000 a year for the first half of the contract and $19,500 for the second, and pick up 45 percent of the utility costs. But the club will keep all the money from concessions sold at the games and the revenue from park advertising.

The county also committed to making $2.8 million in improvements at the stadium through 2013 in the contract, which was approved unanimously Tuesday.

Commissioner Bonnie Mager said she was hoping the county would negotiate a contract that gave it a small percentage of concession revenue, but called Bobby Brett “a shrewd horse trader.” Commissioner Mark Richard said payments to the county would be higher than for any other baseball team in the Pacific Northwest, and said the team and the stadium represent “a tremendous community asset.”

Board Chairman Todd Mielke said the new lease offers significant increases in payments to the county compared to previous agreements and clears up some questions of responsibility for expenses at the ballpark.

The team has leased the stadium for about 24 years.