COPENHAGEN, June 22 (Reuters) - Novo Nordisk said on Thursday the European Union's drug watchdog had last month raised a thyroid cancer safety signal for several of its drugs including semaglutide, the active ingredient in its popular diabetes and obesity drugs, Ozempic and Wegovy.

Shares in Denmark's Novo fell more than 2% in a weaker Copenhagen market after Danish media outlet B.T. reported that the European Medicines Agency (EMA) had raised the safety signal, which is a way to monitor potential adverse events from the use of approved drugs.

A signal from EMA does not mean that the medicine is the cause of any reported adverse events.

"Novo Nordisk is aware of the signal and the request by EMA and will deliver a thorough assessment of all relevant data to elucidate this topic," Lars Otto Andersen-Lange, media relations director at Novo Nordisk, told Reuters.

Andersen-Lange said the B.T. report referred to a May 8 statement from EMA, which raised a thyroid cancer safety signal for several drugs in the GLP-1 class, including semaglutide.

But a "causal association" between semaglutide and thyroid cancer had not been demonstrated in large-scale clinical trials and post-marketing surveillance, he said.

"Patient safety has top priority for Novo Nordisk, and we take all reports about adverse events from use of our medicines very seriously," Andersen-Lange added.

EMA's safety signal had also included GLP-1 drugs from competitors Eli Lilly, Astrazeneca and Sanofi . The three companies did not immediately respond to comment requests from Reuters on Thursday.

"It is probably far too early to raise a very strong concern about this. But it's a good thing that they are looking into it," Sydbank analyst Soren Lontoft Hansen told Reuters.

EMA did not immediately respond to a request for comment. (Reporting by Nikolaj Skydsgaard; Additional reporting by Maggie Fick; Editing by Alexander Smith)