De La Salle, a Roman Catholic college in Salford, Greater Manchester, must merge with another college or go under, according to its governing body.
The college, which was told to take urgent action after a damning inspection report last July, acknowledged the depth of the crisis after enrolments plunged well below target this term. Earlier, it had denied closure or merger were being considered.
Governors have now approached a neighbouring Catholic sixth-form college - Loreto, in Manchester - over a possible merger.
De La Salle, whose principal and vice-principal stepped down shortly after the inspection report was published, has also appointed John Neary, vice-principal of thriving Notre Dame sixth-form college in Leeds, as acting principal until a permanent appointment is made.
By doing so it becomes the second college to receive help from a "troubleshooter" from another institution. Rotherham College in South Yorkshire, facing the spectre of closure, was helped to draw up recovery and strategic plans this summer by senior managers at neighbouring Thomas Rotherham Sixth Form College.
The model of experienced senior staff from successful colleges acting as "rescue squads" for ailing institutions was flagged up as a possible future solution to some sector crises by Sir William Stubbs as he stepped down as chief executive of the Further Education Funding Council last month.
The FEFC, anxious to stress its hands-off approach to college planning, said this week it had had no influence on De La Salle's decision to pursue a merger.
A spokeswoman said the FEFC had been approached by governors afterwards and had moved immediately to help ensure students already enrolled at the struggling college would be guaranteed an opportunity to continue their courses, either at De La Salle or at another local institution.
She said: "The council's main concern at the moment is that students should not be disadvantaged by what is happening."
The FEFC had not yet been informed by the college of any merger negotiations, she added.
During this autumn, the FEFC's north-west regional committee will keep in close contact with De la Salle, responding to requests for guidance and advice, while the governors choose a course of action.
The college, which now has just 360 students, 30 lecturers and 15 support staff, has been beset by financial problems. Inspectors said its management had suffered because of "a lack of senior staff with expertise in financial and personnel matters".
Significant numbers of students were failing to complete courses and recruitment plumeted in 1995-96.
Loreto College, which was judged "well-governed and well-managed" with high quality teaching in an FEFC inspection report last year, has confirmed merger is feasible. Principal Sister Patricia Goodstadt said: "We would consider positively options that might help us contribute to the continuation of the tradition of Catholic education in Salford."
The acting principal and chair of governors at De La Salle were unavailable for comment.