The chancellor has announced he has found 20 per cent of budget cuts saving around £11.5bn in the year from April 2015.
Mr Osborne told BBC Breakfast that no chancellor had got so far in agreeing so many plans so far ahead of a spending review - which is due towards the end of June.
Justice, energy and communities are among the departments agreeing to “significant savings”, he said, adding that health, schools and foreign aid would be protected from cuts.
He said that negotiations over savings continued with the Ministry of Defence and the Home Office, but added he would not do anything to put at risk people’s safety “at home or abroad”.
Mr Osborne is expected to announce the identity of the departments that have reached agreement later today, but the financial details will be held back until the review on 26 June.
He told ITV’s Daybreak: “Seven government departments have agreed provisionally to cuts of up to 10 per cent.”
The BBC reported that is understood that savings agreed so far in talks with departments and in previous announcements mean the Treasury still has to find £8bn of the £11.5bn to be saved in the spending review.
Mr Osborne has indicated there will be no support for a second Crossrail scheme for London in the spending review.
He believes work on the current £16bn Crossrail project should be completed first, in 2018, before he considers further major transport schemes for London.