At Southern Maine Community College in South Portland on Thursday, Jim Shilliday, whose wife is an adjunct professor in the Maine Community College System, holds a sign advocating for higher pay for adjunct professors in the MCCS. Gregory Rec/Staff Photographer

Adjunct instructors who teach in the state’s community colleges held a rally Thursday at Southern Maine Community College to call for higher wages as part of a labor contract that’s under negotiation.

Organizers said the community colleges rely on the instructors, who work on limited-term contracts. They often have graduate degrees and extensive professional and teaching experience but can earn less than minimum wage for the hours they devote to teaching the students, they said.

The president of the Maine Community College System responded in a written statement that the system provided significant increases in the previous contract and has offered 4.5 percent annual increases for two years as part of the proposed contract.