* Tax (if you're thinking of government financial support)
* Charge (if you're thinking of making something more expensive)
* Deregulate (if you're thinking of removing financial support from an industry)
* Reduce (if you're thinking of decreasing financial assistance)
* Deprive (if you're thinking of removing financial support entirely)
For example:
* Instead of subsidizing the industry, the government decided to tax it.
* The company decided to charge customers for the service instead of subsidizing it.
* Deregulating the industry would remove the government subsidies it currently receives.
* The government decided to reduce its subsidies to the arts.
* The company was deprived of its government subsidies and had to close down.
The best antonym will depend on the specific situation you're describing.