A college which has occupied a seven-acre Green Belt site in Mill Hill for more than 130 years has been put up for sale.

St Joseph's College has been training Catholic priests and missionaries at the Lawrence Street site on a small hill overlooking fields, since 1869.

Now it is due to move away because it does not want to spend charitable donations, its main source of income, on maintaining dilapidated parts of the Grade II listed building.

A public meeting into the proposed sale will be held at the college tonight from 7pm to 8pm.

The site was put on the market last week and is currently only available for educational or institutional use due to planning constraints, although Barnet Council has indicated it has no objections in principle to the demolition of certain parts of the building.

A decision in 2005 to move the training of its Catholic missionaries abroad was followed by the announcement this year to put up for sale the seven-acre plot which includes a chapel, library, recreation rooms, offices and kitchens, as well as the 230 bedrooms.

It is currently under the instruction of estate agents Knight Frank, which will invite offers after an 18-week show period.

Rector Father Mark Connolly from the St Joseph's Missionary Society, which runs the college and promotes evangelical work around the world, declined to comment on the building's proposed sale or its cost, saying only that the order was looking to move somewhere within Greater London by the summer, but had not yet found a site. "The meeting is a way of involving the community in the decision of our move," he said.

David Welch, chairman of the Mill Hill Preservation Society, said it would be fighting any residential development or further erosion' of the Green Belt land.

In 2003, the missionary society was refused planning permission to build up to 44 luxury flats on the site to finance its upkeep.

Father Bernard Phelan, then vicar general of the society, said at the time: "We are staying in Mill Hill, that is for certain."

At tonight's meeting, representatives from the college and the estate agents will speak to residents about the plans.