A U.S. advocacy group opposed to a nuclear-armed Iran is calling on South African company Sasol to end its business there, according to a press release posted on Wall Street Journal.

The advocacy group United Against Nuclear Iran says Sasol is delaying its exit from Iran after promising 19 months ago to leave while simultaneously investing in U.S. energy and lobbying U.S. officials for tax breaks.

An energy and chemical company, Sasol develops technology to produce products such as liquid fuels, chemicals and low-carbon electricity. The company has 34,000 people working in 38 countries.

Sasol has committed to extensive business operations in the U.S. including building a multi-billion dollar gas-to-liquids plant in Louisiana, the press release says. Here’s an excerpt:  “The company appears to be conducting a U.S. lobbying campaign to obtain eligibility for tax subsidies under Section 6426 of the Internal Revenue Code. Sasol’s purported effort to have gas-to-liquids fuel included as a qualified alternative fuel under the I.R.C. could result in hundreds of millions of dollars of tax savings for the company.”

Sasol is in a $900 million joint venture through Arya Sasol Polymer Company with National Petrochemical Company, a state-owned Iranian entity that operates two polyethylene plants in Iran, according to the press release.

Iran’s petrochemical sector has been effectively blacklisted by the U.S., the press release  says.

In April, U.A.N.I. put up a billboard near Sasol’s Louisiana offices that read, “Before you build here, stop building in Iran. Sasol must choose: Louisiana or Iran’s terrorist regime.”

In a letter to Sasol executives, U.A.N.I. CEO Ambassador Mark D. Wallace, wrote: “It is shameful for Sasol to directly support the Iranian regime while simultaneously lobbying U.S. officials to secure U.S. federal tax breaks. It has now been more than 19 months since Sasol announced its intention to leave Iran.”

U.A.N.I. has been publicly calling on Sasol to pull out of Iran since January, the release says.

U.A.N.I., in partnership with the London-based Institute for Strategic Dialogue, says it works to prevent Iran from fulfilling its ambition to obtain nuclear weapons. The organization describes itself as nonprofit and non-partisan.