The North Dublin aircraft maintenance firm SR Technics is likely to close with the loss of up to 1,500 jobs if it loses a crucial Aer Lingus maintenance contract currently under tender, according to an internal document seen by RTÉ News.

Last autumn Aer Lingus announced it was putting out to tender its 10-year maintenance contract with SR Technics, which expires this October.

The tender was broken down into four contracts. SR Technics has already been told it has lost two contracts for wheel and brakes and components maintenance.

It expects to find out tomorrow whether they have retained the airframe contract.

By the end of this month Aer Lingus will reveal whether they are sticking with SR Technics for their key line maintenace contract.

An internal SR Technics document dated 7 January describes the line maintenance contract as a core component of their business model.

SR Technics, formerly known as Team Aer Lingus, employs 1,200 and 1,500 staff.

It is part of a global Zurich based group which employs 5,000 people worlwide.

Its total expenditure in Ireland is more than €100m per year with payroll accounting for around €70m.