Mumbai, Oct. 12 -- The Reserve Bank of India (RBI) has introduced fresh restrictions on rupee derivatives to curb currency speculation and maintain an orderly foreign exchange market. The central bank has reduced the threshold for foreign exchange derivative transactions without underlying exposure from 100 million to 5 million dollars across authorised dealers and recognised stock exchanges. Under the new directions, authorised dealers will not be allowed to rebook rupee-involving foreign exchange derivative contracts cancelled after the issuance of the directions. However, rollover of contracts upon maturity will continue to be permitted. The RBI has also directed users hedging contracted exposures to confirm that the same underlying ex...