(Reuters) -Texas has added Britain's NatWest to a list of firms that "boycott" energy companies, potentially restricting the bank's business with public agencies, the comptroller said on Wednesday.

NatWest was added to the list because of limits it has added on energy financing, a spokesperson for Texas Comptroller Glenn Hegar said via email.

The spokesperson cited a NatWest policy stating that after the end of 2025 it will "not renew, refinance or extend existing reserve based lending specifically for the purpose of financing oil and gas exploration, extraction and production."

Hegar's office did not immediately comment on how much business, if any, could be affected by the placement of NatWest on the list.

A representative for NatWest, formerly known as Royal Bank of Scotland, declined to comment.

Under a new Texas law, Hegar's office is responsible for determining which firms or funds effectively discriminate against energy companies, a major part of the Texas economy, even if they remain invested in the energy sector. Listed companies face limits on business they can do with state entities such as pension funds.

The process is part of a broader push by Republican politicians against investors' concerns for environmental, social or governance (ESG) considerations.

Many of these efforts have failed to bring about big changes and new restrictions are not always tight. For instance, the new Texas law contains provisions for officials to keep contracts in place if financially prudent.