Apartment for sale listings are surging across capital cities, led by Sydney with a 39 per cent jump in new stock during the past four weeks, in a sign investors may be offloading properties in a weakening rental market.

Domain data shows that between the four weeks to May 17 and the four weeks to June 14, apartment listings rose by 27 per cent in Melbourne and were up by 15 per cent in Brisbane and 37 per cent in Perth.