Soldiers from The Parachute Regiment, Gurkhas and Irish Guards will be withdrawn in a phased operation starting next month. After further departures, the commitment would stand at about 5,000 by the end of the year, with replacements provided by Canada, Finland and Norway.
An MoD spokesman later set out other measures to reduce overstretch, including bringing forward the formation of a fifth engineer squadron, a unit essential for missions such as in Kosovo, from 2002 to next year.
Other measures were intended to reduce the number of personnel leaving the Army. Troops returning from service overseas, including those coming back from Kosovo, will be guaranteed 20 days' immediate leave on top of their annual entitlement, while families left at home qualify for better travel concessions.
Mr Robertson told MPs: "Between August and October we will be bringing home 1st Parachute Regiment, the 1st Royal Gurkha Rifles and the Irish Guard battle groups, together with their supporting elements. These withdrawals, along with withdrawals of units of the Royal Air Force and Royal Navy announced last month, will go a long way to help relieve the overstretch in the armed forces. Further withdrawals, including that of the headquarters of the Allied Command Europe Rapid Reaction Corps, will of course follow."
The first troops to withdraw will be from The Parachute Regiment, who will return by the end of August. The Gurkhas, who were the first British forces into Kosovo alongside the Paras, will return home next. The HQ of the Rapid Reaction Corps, a Nato body led by Britain, will withdraw by January.