* FTSE 100 down 1.7%, FTSE 250 down 1.5%

* Vistry slips on first-half loss warning

* Jet2 ( DRTGF ) rises on stronger summer travel demand outlook

(Updates after markets close)

July 8 (Reuters) - UK's FTSE 100 saw its biggest one-day

fall since May on Wednesday after U.S. President Donald Trump

said an initial agreement to end the war on Iran was over,

re-igniting concerns about escalating tensions in the Middle

East and lifting oil prices.

The blue-chip FTSE 100 index fell 1.7% to 10,489.04

points at close, its biggest single-day fall since May 15. The

midcap FTSE 250 slipped 1.5%, its worst day since

mid-March.

* More than 80% of the FTSE 100 components closed in the

red.

* Most sectors were in the red; industrial metal miners

were the biggest drag, while the energy index

was the top boost.

* BP and Shell rose 3.5% and 2.3%

respectively, and were among the top performers on the FTSE 100

as the energy sector received a boost from oil prices, which

jumped around 8% on renewed fears of disruptions to Middle East

oil supplies.

* Precious metals miners fell 7% as gold

prices dropped more than 1% amid renewed concerns about

inflation and the prospect of higher interest rates.

* Among individual stocks, Jet2 ( DRTGF ) climbed 8.2% after

the British travel firm said tourists were more willing to

commit to travel plans following the easing of Middle East

tensions.

* Vistry dropped 7.1% after Britain's largest

affordable housing builder warned of a first-half pre-tax loss

of £30 million ($40 million).

* IG Group ( IGGRF ) fell 2.2% after the online trading

platform proposed setting up a new holding company in Jersey as

part of a strategic overhaul to unlock shareholder value.

* Meanwhile, Britain's jobs market downturn eased slightly

last month, according to a survey of recruitment companies on

Wednesday that showed an upturn in temporary hiring and starting

salaries.