A cafeteria contractor has delivered spoiled foods to several D.C. public schools, failed to properly train its staff and distributed some meals without milk and fruit, school officials say.

In one case, they say, students were served moldy breakfast bars.

D.C. public schools notified Chartwells School Dining last month of the deficiencies and warned the company that it is in danger of losing its multimillion-dollar contract with the school system if actions are not taken to improve its performance.

“The expectation was that issues that we have struggled with in the past would be corrected and improved by now,” Glorious Bazemore, deputy chief procurement officer for the school system, wrote in a letter to Chartwells officials. “However, we have continued to struggle with daily problems that disrupt the rhythm of a regular school day.”

In a letter responding to the complaints, Keith Cullinan, president of Chartwells School Dining, said the earthquake and hurricane at the beginning of the school year “created major operational issues . . . resulting in some late and incomplete meal services.”

But company officials said no student received spoiled food or went without meals.

“At no time have there been children who have not eaten, gone without nutritional food or haven’t received a healthy meal,” Benita Byas, a spokeswoman for Chartwells, said in an e-mail. “That is our No. 1 priority.”

The company has repeatedly come under fire from school and elected officials for its costs and services, but officials are particularly troubled by instances of spoiled or contaminated food being served to students.

Officials said that rotten pears and “unappealing” cauliflower were delivered to two separate schools, and that, in another instance, a student found a plastic bread clip in a sandwich.

Additionally, cafeteria staff members did not deliver meals to early-childhood classrooms at one school, schools officials said. At another, custodians, not cafeteria staff members, were cleaning tables. Staff members also improperly portioned food, resulting in 40 missing hot meals for breakfast at one school, officials said.

D.C. Schools Chancellor Kaya Henderson said she’s been unhappy with Chartwells for some time.

“There are lots of issues. We’re in a bad structure, a bad cost structure” that needs to change, she said. By that, she means the arrangement with Chartwells in which the city has to pay the company for every meal it buys, regardless of whether it actually ends up being purchased by a student.

Chartwells has a multiyear contract with the school system with an option to renew annually. The contract, for $32 million in the 2011-12 school year, comes up for renewal at the end of the school year. Henderson said the District will be sending out a request for proposals from other firms. Chartwells is also welcome to bid, she said.

Chartwells is one of three companies that provide food service to the District’s public schools. Outside of personnel, its contract is one of the school system’s largest expenses.

D.C. Council member Mary M. Cheh (Ward 3) said in a recent letter to the council that she plans to push to expand the school system’s ties with DC Central Kitchen and Revolution Foods, which run two pilot programs at 14 schools. Cheh said DC Central and Revolution charge about $1 less per meal than Chartwells charges and provide better service.

“Even without [the deficiencies], we have to move away from our arrangement with them,” Cheh said. “It just adds to my disappointment with them.”

In addition to spoiled food, late deliveries and missing items, D.C. officials contend that Chartwells has misused the point-of-sale machines in the schools and has overstocked storage spaces, potentially costing the District revenue. Chartwells has also failed to comply with the District’s Healthy Schools Act, which requires breakfast in elementary schools to be brought to classrooms or served at cafeteria tables, as well as the District Living Wage Act, which requires a minimum wage of $12.50 for the food service positions, school officials said.

Company officials have said they adjusted wages for employees who were below the minimum wage requirement once they were notified by the union that the salaries were too low. Company officials said they were paying employees using the same rate structure the school system used prior to the start of the contract.

Staff writer Bill Turque contributed to this report.