LIBERTYVILLE, IL-Motorola Mobility has agreed to keep its 3,000 employee headquarters here (instead of moving somewhere like Silicon Valley) and to spend more than $500 million on research and development during the next three years. The state of Illinois, in return, will provide the firm with a $100 million tax break over the next 10 years.

Motorola Inc. split in January into Motorola Mobility, the cell phone and home electronics business based here, and Motorola Solutions, which includes the rest of the company’s products, based in Schaumburg, IL. It was believed that Chairman and CEO of Motorola Mobility Sanjay Jha, who lives in San Diego, would move his firm to California, and the company recently leased about 240,000 square feet in a new building in Sunnyvale, CA.

However, the company agreed to stay, in part due to the $10 million per year investment package. Gov. Pat Quinn on Friday signed Senate Bill 4, expanding the Economic Development for a Growing Economy tax credit to accommodate Motorola. The bill allows qualifying companies to apply the tax credit against either the company’s annual withholding tax liability or their annual corporate income tax liability.

The company will continue to maintain a design center in downtown Chicago. The firm has 20,000 employees globally. As part of this tax deal, Jha promised to keep 3,000 employees in Illinois.