As Iranian officials continue to assert that BASF has big plans for investing in the country’s petrochemical sector following the lifting of economic sanctions, the German chemical giant continues mum.

In December 2015, Iran’s Farsi News Agency quoted Mohammad Hassan Peyvandi, vice president of National Petrochemical Company (NPC) as saying the company had been in talks with BASF about a not further specified “giant joint investment project.” An investment figure of $6 billion was floated.

The latest reports from Tehran quote another NPC executive, Marziyeh Shahdaei, as saying BASF has agreed to take a 60% stake in a petrochemical township in southern Iran’s Parsian Special Industrial Zone and NPC’s director for planning affairs, Hamid Reza Rostami as saying the $4 billion project will involve technology transfer and a “guaranteed market.”

BASF has financed six petrochemical townships in other countries so far and is planning to construct the seventh in Iran, the reports said, adding that Iranian firms will share the remaining 40% stake.

The German group has declined to comment on any of the Iranian remarks, treating them officially as rumors.

According to NPC, the plans include steam crackers and olefins, along with projects related to propylene, gas-to-polymers and methanol-to-olefins.

Reports persist also that Germany’s Linde and Japan’s Mitsui are also negotiating with Iran over investments in the country’s petrochemical industry. There has been no indication of any links to the mooted BASF plans.

Officially, neither of the other two companies mentioned has confirmed any firm plans. Like BASF, gases and engineering group Linde has, however, acknowledged interest in moving back into a new sanction-free Iran.

Prior to the imposition of sanctions, both German players were very active in the country’s petrochemical sector, to which Iran hopes to attract about $70 billion in foreign direct investment by 2025.

One reason companies have been reluctant to confirm investment plans is that it is as yet unclear how new projects can be financed, due to the iron grip of a reluctant US on the international banking system.

Some US clearing banks have warned banks in other countries that under anti-terror provisions the dollar accounts of companies doing business with Iran will face close scrutiny. While giant conglomerates such as BASF, Linde and Mitsui could probably work around such hindrances they may refrain from quick action due to political considerations.