Iran's relations with India have soured in recent months over India's support for international calls on Tehran to freeze its nuclear program.
A major contract to deliver Iranian gas to India through a pipeline via Pakistan has also hit snags.
For a complete archive of RFE/RL's coverage of energy issues in the Caspian Sea region and Russia, click here.
HOW MUCH OIL? The U.S. Energy Information Administration has estimated that the Caspian could hold between 17 billion and 33 billion barrels of proven oil. ("Proven reserves" are defined by energy experts to be 90 percent probable.) Other experts estimate the Caspian could hold "possible reserves" of up to 233 billion barrels of oil. ("Possible reserves" are considered to be 50 percent probable.) By comparison, Saudi Arabia has 261 billion barrels of oil and the United States 23 billion...(more)