WASHINGTON—President Barack Obama reached agreement Monday with Republican leaders in Congress on a broad tax package that would extend the Bush-era income tax cuts for two years, reduce worker payroll taxes for one year and give more favorable treatment to business investments.

Other elements of the deal include a temporary reinstatement of the estate tax at 35%—the level favored by most Republican lawmakers—as well as an extension of jobless benefits for the long-term unemployed.

"We...