New Delhi and Tehran have been trying to narrow differences over Farzad B development rights since its discovery by Indian firms led by ONGC Videsh, the foreign investment arm of Oil and Natural Gas Corp., in 2008, Reuters reported.
Indian companies were hoping to get rights to develop the asset as the South Asian nation was one of the handful of nations that continued to deal with Iran during years of sanctions.
The new terms confine Indian companies to just production of gas and development of the field, said the two sources.
Although a formal offer is yet to be made, sources said, the new bid would be between $3 billion and $4 billion and would not include gas processing and development of downstream projects.
At the request of Iran, Indian companies submitted a $11-billion development proposal last year that covered the development of upstream activities and downstream infrastructure.
The field is estimated to hold 22 trillion cubic feet (tcf)of reserves, of which 16 tcf are deemed recoverable.
India and Iran will discuss the revised development plan for the field next week, during Iran's Oil Minister Bijan Namdar Zanganeh's visit to New Delhi.
To strengthen ties with India, Iran has offered a higher freight discount on oil sales, besides agreeing to consider India's demand for a stake in a producing field, sources told Reuters last month.
In return, India has agreed to boost oil imports from Iran, India's Petroleum and Natural Gas Minister Dharmendra Pradhan said last month after a meeting with Zanganeh in Delhi.