Nimbuzz, the messaging app provider, is in talks with Indian mobile operators to launch a co-branded app providing low-cost international VoIP calls, according to The Economic Times.

The approach would help Nimbuzz increase its subscriber base (which currently stands at 150 million users) while operators could increase international calling revenue hit by free OTT messaging services.

Vikas Saxena, Nimbuzz’s CEO, said the company is in discussions with operators keen to boost their international call businesses. He stressed that the initiative won’t involve incumbent operators such as Bharti Airtel, Vodafone India or Idea Cellular.

Nimbuzz started to work with Spectranet, an ISP, last year to offer international calls starting from INR0.01 per second. Saxena said other similar partnerships are in the pipeline. International calling currently contributes 30 per cent of the company’s revenue.

In June last year, Nimbuzz formed a partnership allowing it to target subscribers of the Sri Lankan operator division of Hutchison Whampoa.

It previously partnered with India’s Aircel and Pakistan operator Mobilink, to provide a discounted Nimbuzz Bundle to allow unlimited usage of the app.

Saxena expects to see a doubling of his company’s revenue in 2014 and believes Nimbuzz will lead the mobile messaging market in India, behind WhatsApp.