The UK is "almost certain" not to continue participating in the Gemini Observatory after 2012 according to a statement by the Gemini board of directors. The UK, which is a founding member of the facility, has a 23% stake in the project with a total of £35m invested to date.

The Gemini Observatory consists of two 8 m telescopes – Gemini North in Hawaii and Gemini South in Chile – that work in the optical and infrared regions. Gemini is operated by a partnership of seven countries including the US, UK, Canada, Chile, Australia, Brazil and Argentina.

Withdrawing from the observatory would save the Science and Technology Facilities Council (STFC), which funds the UK's involvement in Gemini, around £4m per year in running costs.

"It is regrettable that the UK is likely to pull out of Gemini, which reflects the tight budget of STFC," says Andrew Fabian, president of the Royal Astronomical Society. "While we do of course have access to southern skies through the European Southern Observatory, we hope that UK astronomers retain access to a large telescope in the northern hemisphere, either through Gemini North or some other agreement."

In a statement, the STFC said: "The UK has stressed that this is an indicative position only, and does not pre-judge the outcome of the STFC programme prioritization exercise now under way."

The STFC council will now consider the recommendations from its current programme review with a final decision over whether to withdraw expected in March 2010. However, the statement noted that: "[The Gemini board] unanimously accepted the UK's position that it is almost certain to not wish to continue beyond the current expiry data [of 2012]."

In late 2007 the UK also threatened to pull out of Gemini, before reinstating itself a few months later after agreeing to sell up to 50% of its observing time to other member states.