Norway's sovereign wealth fund has ended observation of Supermax Bhd, two years after placing the Malaysian medical glove maker under watch over allegations that the company was contributing to human rights violations.

The trillion-dollar wealth fund said in a statement on Wednesday that it has also ended the observation of Southern Co and BHP Group for their coal usage and production.

Norges Bank, guided by its Council on Ethics, may exclude companies from the fund's investment universe, or place them under observation, based on factors including human rights abuses, weapon sales, and coal-related activities.

"According to the Council on Ethics, the company (Supermax) has during the time of observation reported that it has implemented several measures to improve conditions," Norges Bank Investment Management (NBIM) said in a statement on Wednesday.

"The risk that the company is contributing to human rights violations is no longer considered unacceptable."

NBIM's decision comes over a year after the United States lifted a ban on Supermax, allowing it to resume sales. The company's imports were barred from the U.S. in October 2021 over the alleged forced labor practices.

Southern Co, put under observation in 2016, has since reduced its coal-based power capacity and production that now stand "well below" the fund's threshold.

BHP, which was being monitored since 2020, has also reduced its annual production of thermal coal ever since. The power capacity fell below the fund's threshold in 2021.

Supermax, Southern Co and BHP did not immediately respond to requests for a comment.

As part of Norges Bank's work on the product-based coal criterion, the fund monitors company events and companies entering the market.

The world's largest sovereign wealth fund also revoked exclusion of coal-based power generators TXNM Energy, Public Power Corp, TransAlta, Eneva SA , Capital Power, and coal miner Jastrzebska Spolka Weglowa.

Monitored over the past seven years for their coal output or coal-based power production, these companies have since reduced the commodity's usage and production to levels that no longer necessitate exclusion by the fund.

The companies did not immediately respond to Reuters' requests for a comment.

(Reporting by Gnaneshwar Rajan and Sameer Manekar in Bengaluru; Editing by Shreya Biswas, Devika Syamnath and Sherry Jacob-Phillips)