PITTSBURGH — The Pennsylvania Department of Environmental Protection has added a disclaimer to its Marcellus Shale natural gas reporting Web page.

The agency now tells visitors to the website that it can’t guarantee the “accuracy, completeness or timeliness” of production data that companies submit and that “no warranty of any kind is given by DEP with respect to the production data.”

Financial markets and energy companies use the production reports as part of long-term decisions involving billions of dollars.

The disclaimer comes after several experts in the oil and gas industry criticized DEP in August for not alerting the public to problems in a biannual report. One of the state’s largest natural gas producers at first submitted unusable data and, as a result, the statewide production totals appeared to be far lower than they actually were. The problem was later corrected.

DEP spokesman Katy Gresh said the agency decided to provide the clarification because of some public confusion about the reporting process.