HILO, Hawai'i — The fate of two major Mauna Kea telescopes is in limbo following a decision in mid-December to cut funding for at least one of them.

The United Kingdom's Science and Technology Facilities Council reassessed its funding priorities for 2010-15, and one of the losers was the United Kingdom Infra-Red Telescope, which the Joint Astronomy Centre operates along with the James Clerk Maxwell Telescope.

The plan involves a "managed withdrawal" from UKIRT — on a schedule yet to be determined — and a commitment to continue operating the JCMT through the end of 2012.

With its 12.4-foot diameter primary mirror, the 30-year-old UKIRT is the world's largest telescope dedicated to infrared astronomy. JCMT's 49-foot radio reflector makes it the world's largest single-dish submillimeter telescope.

Most of the Joint Astronomy Centre's 60 employees are on vacation this week, but a statement posted on the observatory's Web site called the UKIRT decision "a profound disappointment for everyone associated with the observatory."

"We are working with STFC to define the timescale and the implementation details, and we are also looking at alternative modes of operation. We emphasize that no decision has yet been taken to close the facility."

Should the funding agency withdraw from UKIRT, options under terms of the sublease include a sale to the University of Hawai'i; a sale to a third party acceptable to the university; turning over the telescope to the university, pending approval of the state Board of Land and Natural Resources chairperson; and a total removal and restoration of the property at the expense of STFC.

The U.K. agency funds 55 percent of operations for JCMT, with Canada and the Netherlands picking up the remainder.

Although not specifically stated in the STFC's public announcement, continued funding of the JCMT beyond 2012 is contingent on, among other things, the performance of a complex imaging instrument known as SCUBA-2, the JAC astronomers said in their statement.

Bob McLaren, associate director of the UH Institute for Astronomy, said the STFC's announcement posted on the Internet is about all that anybody knows.

"They intend to withdraw ... by the end of 2012," McLaren said.

The United Kingdom is one of seven major partners involved in operating Gemini's twin 8.2-meter telescopes — one on Mauna Kea and the other in Chile. A Gemini spokesman said that all inquiries should be directed to the National Science Foundation.