Vodafone India on Wednesday announced the availability of 4G SIM cards across its stores in and around Mumbai. India's second-largest telecom company will soon roll out its 4G network in the country's financial capital.

Depending on convenience, Vodafone subscribers can go and upgrade their SIMs to high-speed 4G-ready SIM's at 56 Vodafone stores located across Mumbai.

"Our 8.6 million customers in Mumbai have a lot to look forward to. We want our customers to be 4G-ready so they can start experiencing the benefits of high-speed mobile Internet services as soon as they are launched commercially. Hence, this facility to upgrade to 4G-ready SIMs has been rolled out in advance. We are excited and fully geared up to launch our 4G services on the superior 1,800-MHZ band in Mumbai soon," Ishmeet Singh, Business Head at Vodafone India, told The Economic Times.

In October 2015, another Economic Times report had said Vodafone would begin 4G services in India by December 2015, whereas the exact date of launching the service remains uncertain.

According to reports, Vodafone has been sending out formal communication to its subscribers in Mumbai, in addition to that, another service is being offered — home delivery of 4G-ready SIMs for premium high-value customers in Mumbai.

Vodafone India has partnered with various global technology service providers, and will launch 4G network in Kolkata, Delhi and Bengaluru by the end of March 2016, The Financial Express said.

The company said a formal announcement is expected soon.