The development of a £12m sports complex in Matlock, Derbyshire, could be delayed following the withdrawal of funding partner the Marston's pub company.

Derbyshire Dales District Council, owner and operator of the proposed facility, intended to invest £7m into the project, which was to be generated from the sale of land to Marston's and of Sherwood Hall Leisure Centre, which was recently sold for £1m.

The pub company backed out of negotiations due to the size of the site and the ground conditions not being suitable for the brewery's business. The council is now looking for a new buyer.

This £7m would have joined a recently awarded £500,000 grant from Sport England and other external funding sources.

The proposed facility, to be called Central Area Leisure Centre (CALC), is due to replace both Sherwood Hall and Matlock Lido, which will be sold to assist in the funding but only after CALC is completed.

CALC, designed by Drivers Jonas, will feature a 25m, eight-lane swimming pool that meets National Short Course competition standards, as well as two sports halls, a multi-use area for aerobics and a 50-station fitness and health suite. There will also be a café and meeting rooms.

In addition to the existing football pitches, the outdoor facilities will boast BMX trails and a multi-use games area.

Councillor Geoff Stevens said: "We believe CALC will be massively significant to residents in this part of the district. This will be a striking development offering a wide range of opportunities in swimming, dry sports and leisure activities as well as being attractive to visitors to the Peak District."

The council has also requested grants from The Foundation for Sport and the Arts, and a bid has also been made to The Big Lottery Community Buildings Fund for the new community room.

The project is part of a wider plan to revitalise the District Council's leisure facilities and follows upgrades in Ashbourne, Bakewell and Wirksworth. This is a key part of the Dales Central Initiative, which has already seen the completion of improvements to Hall Leys Park in Matlock.

If funding is secured, the council is expecting to open the facility in summer 2011.