The budding strategic partnership between Iran and South Africa is set for a major boost.

An agreement on a R6-billion gas-to-liquid project between PetroSA and the National Oil Company of Iran was expected to be signed on Tuesday.

A further R9-billion investment deal between Sasol and the National Petrochemical Company of Iran for the development of a plastics manufacturing plant in the Persian Gulf is under discussion as well as other joint ventures and investments expected to reach R30-billion in the next few years.

Foreign Minister Nkosazana Dlamini-Zuma said PetroSA and Sasol were in the process of establishing regional offices in Iran and were working with their Iranian partners in "groundbreaking work in the petro-chemical sector".

She said that over the past year, South African mining companies had been assisting with the exploitation of Iranian zinc and manganese deposits.

Iran is a major supplier of oil to South Africa.

In 2001, two-way trade between the two countries was valued at R9-billion but was heavily in Iran's favor due to massive oil exports, only marginally offset by about R300-million in imports from South Africa.

Iranian Foreign Minister Kamal Kharrazi said at the opening of the seventh session of the South Africa-Iran Joint Commission in Pretoria on Monday that much work needed to be done to realize the potential of bilateral and trade relationships.

Dlamini-Zuma said there had been significant Iranian direct investment in the South African economy recently, including a R560-million input by an Iranian housing consortium in a Western Cape housing development and an expanded investment in a project in the Eastern Cape.

But Dlamini-Zuma said the trade balance being heavily skewed in favor of Iran was a "worrying characteristic of our relationship".

She said a South Africa-Iran Business Forum would be set up this week.