India had signed the Free Trade Agreement (FTA) with the Association of Southeast Asian Nations (ASEAN) in August 2009, but it was operationalised by only three of its members.
A Commerce Ministry official said that though Singapore, Thailand and Malaysia account for more than 90 per cent of India's trade with ASEAN countries, the remaining seven were also "important markets".
The FTA, which significantly reduces or even eliminates duties on goods such as machinery, steel and oilcake, was to be extended to all ASEAN members by June. However, some of them sought an extension of deadline.
"Some of the nations, such as Cambodia and Myanmar, required approval from their Parliament. As for Philippines, a new government had just taken over," the official added.
The seven countries, which are yet to implement the pact, are Brunei Darussalam, Cambodia, Indonesia, Laos, Myanmar, Philippines and Vietnam.
The Indo-ASEAN trade in goods stood at USD 45 billion in 2008-09. However, it declined in 2009-10 due to global economic problems.
The two sides also engaged themselves in negotiations to widen the base of the pact by including services and investments in the trade treaty.