* FTSE 100 down 0.2%, FTSE 250 up 0.3%
* Uncertain trade picture weighs on sentiment
* Kingfisher rises after naming new CEO
* Mid-cap Senior slips after Boeing (NYSE:BA) 737 MAX faces new setback (Adds news items, analyst comment, updates to closing prices)
By Shashwat Awasthi
June 27 (Reuters) - London's FTSE 100 ended lower on Thursday as initial investor optimism gave way to uncertainty amid conflicting reports on whether Washington and Beijing would commit to a trade truce, while Glencore skidded after a mine collapse in Congo.
The FTSE 100 .FTSE closed 0.2% lower, after slipping as much as 0.5%. The mid-cap FTSE 250 .FTMC added 0.3%, helped by a relatively steady pound.
Markets had initially welcomed signs of progress in the trade talks after the South China Morning Post, citing sources, said the United States and China had agreed to a truce before leaders of the two nations meet at the G20 summit. helped shares of Asia-focussed banks such as HSBC HSBA.L and miners such as Rio Tinto RIO.L gain on the FTSE 100.
However, the blue-chip index's fortunes reversed after The Wall Street Journal reported that Chinese officials would insist on the removal of sanctions on technology firm Huawei, among other proposals, as part of any agreement.
"There are decent signs that the apparent return of poise to risky assets may not run deep," Cityindex analyst Ken Odeluga said.
"We can now expect an awful lot of newsflow on trade and tariffs over the next two days, so it's wise to be cautious about reading too much into statements," Markets.com analyst Neil Wilson said.
Glencore GLEN.L gave up 5%, its biggest one-day fall in almost a year, after a mine owned by the company collapsed in southwest Congo. The company confirmed that 19 artisanal miners had died and warned of possible further fatalities. [nL8N23Y583
But home improvement retailer Kingfisher KGF.L added 4.2% after it named Carrefour 's CARR.PA Thierry Garnier as its new chief executive. Senior SNR.L , which makes a variety of components used in commercial and military jets and counts Boeing BA.N as one of its top customers, tumbled 10% on news that U.S. regulators had identified a new risk to Boeing's grounded 737 MAX.
The stock endured its worst day in more than 2-1/2 years as a rating downgrade from Barclays (LON:BARC) also weighed. of Pendragon PDG.L , hammered earlier this month after a profit warning, slid 5.7% after the car dealership said its chief executive would step down because of a "difference in priorities", delaying its strategic review. maintain our view that Pendragon's problems are multiple and deep-rooted and that any management team will face an uphill challenge in the current trading environment," Liberum analysts wrote.