CARSON CITY — Nevada Gov. Jim Gibbons signed a proclamation Tuesday officially calling for a Feb. 23 special session of the Legislature and outlined more details of his plans to close a projected $880 million budget deficit, including 10 percent cuts at state agencies, some four-day work weeks and more taxes from mining companies.

"These are serious times for the state of Nevada," the Republican governor said during a signing ceremony in his Capitol office.

The proclamation, which sets the agenda lawmakers must consider, can and likely will be amended in the coming days and even after lawmakers convene, the governor said.

"We're feeling our way through this," Gibbons said. "This is not so etched in concrete we can't make a change down the road."

Among other things, Gibbons is calling for four-day work weeks for some state agencies, and increasing worker furloughs from eight hours per month to 10 hours for those workers. That change would equate to salary reductions of 5.7 percent, up from 4.6 percent lawmakers passed in 2009.

Though not part of his proclamation, Gibbons also proposed capping deductions taken by the mining industry, a move that could generate $50 million in the two-year budget cycle that ends June 30, 2011, the administration said.

Gibbons, a staunch no-tax governor, characterized the proposal as closing "inadvertent loop holes."

"These are not new taxes," he said, but, "simply clarifying the deductions they are allowed to take."

A petition initiative backed by Progressive Leadership of Nevada, or PLAN, seeks to amend the state constitution and require mining companies to pay taxes of at least 5 percent of their gross proceeds. The current tax is limited to 5 percent of net proceeds before most expenses are deducted.

The industry can deduct 100 percent of its costs for marketing, operations and other expenses, officials said. The administration wants to cap those allowances to a certain percentage yet to be determined.

Gibbons is also banking on $30 million in the next fiscal year from InsureNet, a Chicago company that has proposed setting up a camera system along state highways to catch uninsured vehicles. Administration officials estimate 22 percent of motorists on Nevada roadways lack state-mandated insurance.

Besides 10 percent agency cuts, Gibbons also proposes additional reductions to public schools and the Nevada System of Higher Education equating to 1.75 percent salary cuts. But the agencies would be given leeway to decide how to achieve those savings in the next fiscal year, $35.7 million in K-12 and $9.5 million in higher ed.

The administration also seeks to "sweep" more than 50 non-general fund accounts from agencies to add $90 million to general fund coffers in the upcoming fiscal year.