Bharti group on Thursday said it would invest Rs 50 crore (Rs 500 million) in improving its quality of telecom services in Delhi, taking its total investment during the current fiscal to Rs 300 crore (Rs 3,000 million).

Bharti Televentures, the service arm of the Bharti group, would make an additonal investment of Rs 50 crore for setting up two new mobile switching centres and installing another 150 cell sites in Delhi over the next couple of months, Sanjay Nandrajog, CEO and director (mobility, north-central region), Bharti Cellular, told newspersons in New Delhi.

Currently, Bharti's cellular phone service, offered under the brand name AirTel, has 650 cell sites in Delhi and the NCR region and seven mobile switching centres, he said.

The expansion of infrastructure would make voice quality better, he said, adding the company has already completed the implementation of a complete suit of voice enhancement features.

"The deployment of voice quality enhancers will improve the voice quality by eliminating the annoying effects of acoustic echo generated by wireless handsets and background noises," Nandrajog said.