CORRECTED-UPDATE 2-FTSE 100 edged up as gains in miners, oil offset global angst

(Corrects first paragraph to remove extraneous word fell)
* FTSE 100 up 0.1%, FTSE 250 down 0.1%
* Miners, oil majors counteract U.S-Iran tensions
* Sterling skids as Brexit worries resurface
* Lookers slumps after investigation by regulator

By Shashwat Awasthi
June 25 (Reuters) - London's FTSE 100 eked out modest gains
on the back of strength in mining companies and oil stocks on
Tuesday, alleviating some anxiety after the United States
imposed more sanctions on Tehran and before Sino-U.S. trade
talks this week.
The FTSE 100 .FTSE erased earlier losses to edge 0.1%
higher, while the mid-cap FTSE 250 .FTMC lost 0.1%.
Shares of heavyweight miners .FTNMX1770 rose after a
strike at a major mine in top copper producer Chile highlighted
supply constraints, while oil firms advanced in anticipation of
a bullish reading of U.S. crude stock data. O/R
Investors had been subdued for large periods of the session
after President Donald Trump targeted Iranian Supreme Leader
Ayatollah Ali Khamenei and other top Iranian officials with
sanctions, which further strained the geopolitical dynamics in
the Middle East. Uncertainty over how talks between Trump and his Chinese
counterpart Xi Jinping will pan out at the G20 summit has also
had an impact, with markets fearful that the protracted trade
war, which has stunted global economic growth, could escalate.
"Partly a holding pattern, partly a surreptitious drift to
safety is a fair way to characterise the market mood as global
tensions simmer ahead of the G20 meeting," Cityindex analyst Ken
Odeluga said.
Sales at British supermarket chains fell during the 12 weeks
to June 16, losing further ground to discounters Aldi and Lidl,
industry data showed, leading shares of Tesco TSCO.L and
Morrisons MRW.L 1% lower. Brexit concerns also re-emerged and the pound, which earlier
capitalised on the broader weakness of the dollar as traders bet
on more dovish signals from the U.S. Federal Reserve, came under
pressure again.
Sterling skidded after eurosceptic Boris Johnson, the
favourite to replace Prime Minister Theresa May, said he was
serious about a no-deal Brexit if the bloc refused to
re-negotiate a divorce deal. On the mid-cap index, Petrofac PFC.L tumbled 6.5% after
the oilfield services provider, dogged by legal challenges over
the last two years, said its business was hit by challenges in
Saudi Arabia and Iraq. Rail operator Stagecoach Group SGC.L gave up 6.6% ahead of
its annual results on Wednesday.
Small-cap Lookers LOOK.L tanked 24% to its lowest in more
than seven years, after the car dealership said Britain's
financial watchdog was investigating its sales processes.