PITTSBURGH (KDKA) — City of Pittsburgh officials are warning Lamar Advertising and Sprint Corp. to remove an advertisement erected earlier this week on the iconic Bayer Co. sign on Mt. Washington.

According to Mayor Bill Peduto’s Office, the City of Pittsburgh Law Department sent cease and desist letters Wednesday to both companies.

The city wants a vinyl advertisement from Sprint, reading “Pittsburgh WINS with Black & Yellow,” removed immediately.

City officials say neither Lamar Advertising nor Sprint applied for the proper permits to put the sign up.

In a press release Mayor Peduto says: “This is an unauthorized and unpermitted sign, erected without public oversight, much like the sign Lamar tried to put on the Grant Street Transportation Center years ago. We had been in good faith negotiations with Lamar about the long term use of the billboard and had requested a hold on any static sign installation by the company.”

Click here to read the city’s full cease and desist letter.

The city says they’ve cited Lamar Advertising for being in violation of an international property maintenance code, requiring “exterior surfaces of structures to be maintained in good condition and treated to prevent rust or corrosion.”

Join The Conversation On The KDKA Facebook Page

Stay Up To Date, Follow KDKA On Twitter

The Department of Permits, Licenses & Inspections has issued a violation notice to Lamar Advertising for putting up the sign without the proper permit.

Officials also say they will seek to impose fines and penalties against both companies.

This isn’t the first time the old Bayer sign has been the subject of controversy. Last year, a heated dispute between the mayor’s office and a potential advertiser stopped a deal to makeover the sign.

Stay with KDKA for the latest on this developing story.