But the London house builder said underlying demand remained strong, even though pretax profit slipped to £531m from £540m in the previous year.
Despite this weakening Berkeley said it remained on target to deliver pre-tax profits of £2bn in aggregate over three years to 30 April 2018.
Managing Director Rob Perrins said: “While sales are down 4% for the year as whole, the market for Berkeley has slowed some 20% in the five months to May 2016 as the EU Referendum approaches, with no new London launches in this period.
“This has had a more distinct impact on the higher end of the market, which has also been affected by increased transaction taxes and the policy shift against buy-to-let investors.”
He added: “New sales activity is now focused on the periods beyond 2017/18 with a number of new launches planned for later in the year, once the EU Referendum uncertainty passes.”
In the year to 30 April, Berkeley sold 3,776 new homes (2015: 3,355) across London and the South of England at an average selling price of £515,000 (2015: £575,000).
It said the drop in average selling price was down to a change in mix with Berkeley completing two student developments of 638 units in the current year, one in Bath and one in London.
In the last 12 months Berkeley has acquired 12 new sites of around 8,600 plots, secured nine new planning consents and 21 revised planning consents.
This increased investment lifted land holdings to 42,858 plots with an estimated future gross margin of £6.1bn, up from 37,473 plots and £5.3bn a year ago.