GLOBE Telecom Inc. is urging its customers to stop using illegal signal boosters, which the firm said weakens mobile signals in surrounding areas.

The Ayala-led telco said the use of illegally signal boosters causes dropped calls, choppy or garbled lines, robotic voices and weak or no signal.

"We understand network challenges that some customers experience in densely populated areas. But we appeal to them to resist resorting to the illegal use of signal repeaters, as this spoils the network experience of mobile users around them, robbing them of the life-enabling benefits of connectivity," said Joel Agustin, Globe senior vice president and head of network planning and engineering.

The sale, purchase, importation, possession or use of portable cellular mobile repeaters and cell site equipment is banned under National Telecommunications Commission (NTC) Memorandum Order 01-02-2013.

Under the NTC order, only licensed mobile network operators and government agencies "performing functions vital to national security or safety" are allowed to acquire and use signal boosters.

"We call on our customers to support fair signal distribution and do their part in achieving our goal of digitalizing the nation with no one left behind," Agustin said.

Globe said it was continuing to expand its reach and capacity to improve customer experience and service delivery, with 116 new cell sites having been built and 812 mobile sites upgraded in the first quarter this year.

Its fifth-generation (5G) coverage continues to grow, the firm added, with 27 new deployments from January to March of this year.

Globe shares plunged by P65, or 3.26 percent, to P1,928 on Friday, outpacing the Philippine Stock Exchange Index's 2.93-percent drop.