Section 7, sub-section (4) of the Arbitration and Conciliation Act, 1996 provides that-
(4) An arbitration agreement is in writing if it is contained in-
(a) a document signed by the parties,
(b) an exchange of letters, telex, telegrams or other means of telecommunication including communication through electronic means which provide a record of the agreement, or
(c) an exchange of statements of claim and defence in which the existence of the agreement is alleged by one party and not denied by the other