The Southern African Customs Union (Sacu) said on Tuesday it was still committed to negotiations with India over a delayed preferential trade agreement (PTA).

"We are still confident we will come to an agreement with India," Sacu deputy director for trade negotiations Rolf-Joacim Otto told a Sapa correspondent on the sidelines of Botswana's global expo business conference in Gaborone.

First launched in 2007, the PTA seeks to increase trade between Sacu and India by giving each party's products and services preference over other regions. Sacu is made up of Botswana, Lesotho, South Africa, Swaziland, and Namibia.

"As Sacu, we are still finding each other. Firstly, the level of economic development between member states is not level and this presents challenges," said Otto.

"We need to find a common position and present it to India as a group. Secondly we still have issues relating to capacity as far as negotiations and our ability to meet demands from India is concerned."

Asked why the agreement had not yet been finalised despite years of negotiation, Otto said India was a big economy and "expecting a lot" from the agreement.

He said Sacu was conducting other negotiations, such as the recently-concluded economic partnership agreement with the European Union, which at times stretched Sacu's resources.

It was not clear when the agreement with India would be finalised, seven years after it was first mooted.

"We are meeting them [India] next year," he said.

It was "dangerous" to give a specific time frame for when a deal would be concluded, as they were normally "complex", involving a number of aspects and jurisdictions.

A memorandum of understanding on the PTA with India was expected to have been signed in December 2013, but did not take place.

Otto was confident that once the deal was signed, Sacu member states would benefit from India's wide market.

Sacu sought to increase trade volumes on products from sectors including agriculture, electronics, and mining.

Trade between Sacu and India was growing, being around $10-billion (R110.3-billion) annually.