NAPLES, Italy — China and Europe have agreed to take their dispute over satellite navigation frequencies to the International Telecommunication Union (ITU) by the end of this year, a senior European Commission official said Oct. 2.

The agreement, reached during a Sept. 20 summit in Brussels, Belgium, between China and the 27-nation European Union, may be a last-ditch attempt to resolve an issue that has been a thorn in the side of Europe’s Galileo satellite navigation program for years.

Because it has festered for so long, it may be too late to do much about the problem given the state of development of both sides’ satellite systems.

Europe’s Galileo constellation of medium Earth orbit satellites has two spacecraft in orbit and two scheduled for launch in mid-October. The program is slated to launch six more in 2013, with at least four more to follow by the end of 2014.

China’s Beidou system, which employs satellites in medium Earth, geostationary and inclined geostationary orbit, has 11 satellites in orbit and began initial operations in December. By the end of 2012, the system will be able to provide positioning, navigation and timing services for a wide swath of the Asia-Pacific region, according to the China Satellite Navigation Office.

Paul Weissenberg, deputy director-general of the enterprise and industry directorate-general of the European Commission, the EU’s executive arm, said the commission believes that taking its case to the Geneva-based ITU is worthwhile.

“We have been talking to the Chinese for a long time,” Weissenberg said here Oct. 2 at the 63rd International Astronautical Congress. He said he visited Beijing in August to prepare the agreement that ultimately was signed during the Sept. 20 EU-China summit.

Weissenberg did not spell out exactly what the commission hopes to secure from the ITU in the way of a decision.

In the past, ITU officials have said their regulatory purview extends only to cases in which actual or potential signal interference is alleged. In these cases, the ITU applies its first-come, first-served rules to determine who has priority access to satellite orbital slots or broadcast frequencies in question.

In this case, neither the EU nor China has alleged interference. Instead, the EU would like China’s Beidou program to operate its secure, government-only service on radio spectrum that does not overlap with frequencies to be used by the Public Regulated Service (PRS) planned for Europe’s Galileo.

PRS, like China’s secure service and the U.S. GPS M-code, is reserved for military and civil-security uses.

A Beidou signal overlap with PRS will not impinge on the operations of either system, but will make it difficult for either one to jam the signals of the other in the event of a conflict.

This is the same issue that stressed U.S.-European satellite navigation discussions during Galileo’s design phase, when some European Galileo backers wanted PRS to overlay the GPS M-code.

The U.S. State and Defense departments threatened to cease all satellite navigation cooperation with Europe unless the PRS signal was moved away from the M-code frequencies. European governments ultimately agreed to the U.S. request.

A joint statement issued after the EU-China summit said the two sides “expressed common willingness to enhance cooperation in the field of space technology, and on the civil aspects” of their navigation systems.

A separate statement on space technology dialogue was issued at the same time, and it is this document that calls for the two sides to take their case to the ITU before the end of this year, Weissenberg said.

Given where the European and Chinese systems are in their development and deployment, it is unclear what can be done at this point to modify the signal overlay, government and industry officials said.

“I suppose one way would be to increase the PRS signal’s power to see whether it can overwhelm the Beidou signal, but the Chinese would then react by increasing their power,” one industry official said. “I am not sure this is a satisfactory long-term solution.”

Peter B. de Selding was the Paris Bureau Chief for SpaceNews.