JOLIET – Gov. Pat Quinn offered his support and a $10,000 donation to workers striking outside a Caterpillar plant south of Chicago, wading into a months-long labor dispute with a company whose chief executive has been a harsh critic of his administration.

The Peoria-based heavy- equipment maker has taken issue with the state government’s handling of the Illinois economy.

And last year, Chief Executive Douglas Oberhelman, in pressing Quinn to work on improving the economy, reminded him that the company had out-of-state suitors.