Britain's FTSE falters as easyJet, housebuilders and banks tumble

* FTSE 100 down 1.1 pct

* Budget airline easyJet slides on profit warning

* Banks hit by downgrades

* Housebuilders also fall

* Gold miners among top gainers (Recasts, adds detail, updates prices)

By Kit Rees

LONDON, June 27 (Reuters) - British stocks opened lower onMonday, extending losses from the previous session as lastweek's vote to leave the European Union hurled Britain intopolitical uncertainty, hitting the shares of British banks,housebuilders and budget airline easyJet.

The blue-chip FTSE 100 index fell 1.1 percent to6,071.19 points by 0823 GMT, with the mid-cap FTSE 250 down 3 percent.

Britain's finance minister George Osborne spoke publicly onthe Brexit vote for the first time on Monday morning, looking tocalm markets with an assertion that the British economy remainsstrong.

Shares in easyJet slumped more than 16 percent -- ontrack for its biggest daily decline since January 2011 -- afterit warned on third-quarter profit, citing an uncertain outlookbecause of the Brexit vote.

Rival IAG, which operates British Airways, fell 9.2percent after Goldman Sachs downgraded the company to "neutral".

Among financials, Royal Bank of Scotland (RBS) andBarclays also came under pressure, down 12.2 percentand 9.6 percent respectively, hit by a spate of brokerdowngrades as well as JP Morgan cutting its rating on all UKdomestic banks.

"The UK's vote to leave the EU will drive tectonic plateshifts in European bank investing. We move to a slowgrowth/modestly recessionary scenario for UK banks," analysts atJefferies said in a note, downgrading RBS to "hold" and Barclaysto "underperform".

Housebuilders were also among the top fallers, with TaylorWimpey, Persimmon, Barratt Developments and Berkeley Group down between 7.4 percent and 10.8percent.

Precious metals miners Fresnillo and RandgoldResources were the top gainers, rising 6.2 percent and5.5 percent respectively, extending gains from Friday assafe-haven assets continued to be in demand.

Among small-cap stocks, Foxtons plummeted by 21.7percent after it said that Brexit would prolong uncertainty inthe property market.

(Editing by David Goodman)