State and local governments in the Washington area have turned to incentives like those to be challenged in a Supreme Court case. Some examples:

* Radio One: The broadcasting company based in Prince George's County said in December that it would like to build a new headquarters in the District near Howard University. It said it was asking District officials for financial incentives to make the move, and a spokesman for the D.C. Office of Planning and Economic Development said the District was also interested.

* Eli Lilly: The pharmaceutical company is getting $5.25 million in economic incentives from Virginia and $2 million in incentives from Prince William County to build an insulin plant. The incentives were not reduced even though the company announced in June that it would scale back the building and hire only about half the 700 workers originally planned.

* International Business Machines: Virginia and Fairfax County each pledged $600,000 last September to entice the technology company to create 1,250 high-paying government-contracting jobs through a $10 million expansion of its site at Fair Lakes.

* Howard Hughes Medical Institute: Loudoun County agreed in 2003 to provide nearly $6 million a year in tax breaks for the $500 million research facility being built in the county.

* Marriott International: After intense competition between Maryland and Virginia, the hotel company decided in 1999 to expand its headquarters in Montgomery County in return for a variety of tax credits and job-training grants worth at least $31.7 million, adjusted for inflation over 19 years.