I just saw the details from a spreadsheet the Sonics are circulating in Olympia on a proposed financing for a new arena. I haven't seen the actual bill. The financing plan seems very similar to what was proposed in 2005, and uses taxes created or increased to build a new ballpark for the Mariners and a stadium for the Seahawks.

It's a $423 million plan that extends or diverts a series of existing King County taxes.

The biggest piece would be $150 million from a 17-year extension on the sales tax credit the Legislature created to pay for Safeco Field. There's also $77 million that would come from extending the credit that was approved for Qwest Field an extra eight years.

The tax credits allow the county to keep a percentage of sales tax that otherwise would have been sent to the state.

The bill would also take some of a King County restaurant tax that is reportedly coming in faster than expected — it was passed to pay off Safeco bonds — as well as portions of the car rental and hotel/motel taxes increased for the baseball and football facilities.

UPDATE: We now have copies of the documents with details of the proposal. You can see the spreadsheet here and the summary of the bill here.