SINGAPORE, Nov 4 (Reuters) - Global exchange Climate Impact X (CIX) and carbon finance business Respira have completed an auction to sell 250,000 tonnes of blue carbon credits at $27.80 per tonne.

The credits are 2021 vintage, meaning they were issued last year, and the price was $10 per tonne, or 40%, premium to spot prices for other credits from that vintage, CIX said in a statement on Friday. They were generated from Pakistan's Delta Blue Carbon Project, the world's largest mangrove restoration project.

"Despite a backdrop of high inflation and global macro uncertainty weighing on the whole carbon market, this represents a strong signal of support for premium credits of high integrity," CIX said.

Blue carbon refers to carbon that is naturally stored by marine and coastal ecosystems, while green carbon is contained in vegetation and forest ecosystems.

The auction was awarded based on the lowest bid submitted for the volumes that was above the reserve price. But 30% of the bid volume was priced at $35 per tonne or more, said CIX, which is 27% above the auction reserve price of $27.50 per tonne, "signalling the premium at which some buyers were willing to pay for high-quality and unique credit types."

Under increasing pressure to cut carbon emissions, firms need carbon credits to offset emissions they are unable to remove from their operations.

CIX, a global marketplace and exchange for carbon credits, is jointly formed by Singapore's DBS Bank, Singapore Exchange Group, Standard Chartered and Singapore state investor Temasek. (Reporting by Emily Chow; Editing by Christian Schmollinger)