Waste Management Inc. and the city of Tampa are negotiating an overpayment of nearly $1 million by the city for commercial solid waste collection.

The city said it overpaid the Houston-based Waste Management by at least $972,000 for waste collection between 2008 and 2012. The company said the overbilling began when the city gave Waste Management inaccurate information at the start of the billing process, confirmed Ali Glisson, public affairs director for the city, in an interview.

She said the two sides are continuing to negotiate on the actual amount. The city claims the amount of overbilling could be as much $1.4 million, but the company has only acknowledged the lower amount.

The problem occurred in cases where a new business replaced an old one, but Waste Management would continue to bill the city for both businesses, according to Mike Herr, Tampa public works and utility services administrator.

Waste Management has a contract worth $1.76 million annually with the city to pick up commercial waste in parts of the city. City crews collect 60 percent of Tampa's commercial solid waste, and Waste Management picks up 40 percent.