FIPB has also sought details from Bharti Airtel regarding Vodafone's stake in the company, sources close to the development said.

Vodafone and Bharti had last month announced an agreement under which Bharti agreed to buy back 5.6 per cent direct stake from Vodafone for $1.6 billion on deferred payment basis, while the UK mobile giant would be retaining the balance indirect equity in the group.

The FIPB move comes on the heels of the British giant approaching the Board late last month for approval to acquire controlling stake in Hutch-Essar from HTIL as well as for its investment plans for telecom business in the country.

Vodafone, which has agreed to acquire HTIL's stake in Hutch-Essar for $11.1 billion in cash and about $2 billion in debt assumptions, needs FIPB clearance under the government guidelines. The deal is subject to FIPB approval for Vodafone's exit from Bharti as well as acquisition of HTIL's stake in HEL.

The regulatory norms make it mandatory for a foreign investor to submit a 'No Objection Certificate' from its existing Indian partner if permission is sought for another venture in the same sector.

An HTIL spokesperson was not available for comments. Vodafone has submitted its board resolution and the NOC from Bharti, sources said, adding this should be sufficient to get the FIPB approval.

Since Bharti has already endorsed the acquisition, the British major has said it is just filling into the Hutch's shoes in India and the deal is compliant with all the norms.

However, FIPB is yet to take a call on the issue. It needs to take note of HTIL's stake sale to Vodafone as also the continuation of Hutch-Essar Managing Director Asim Ghosh and industrialist Analjit Singh as shareholders, who together hold about 15 per cent stake in the venture � effectively giving the UK company 67 per cent control in Hutch-Essar.

The race for Hutch-Essar: Complete coverage