* FTSE 100, FTSE 250 up 0.1%
* Oil majors biggest boost to main bourse
* Midcap retailer Ted Baker surges on M&A reports(Adds company news, updates shares)
By Muvija M
July 22 (Reuters) - Gains in oil heavyweights amidheightened tensions in the Middle East helped London's mainindex hold steady on Monday, while Ted Baker was in demand afterseveral media reports of takeover plans.
The FTSE 100 index of bluechip companies and theFTSE 250 midcap index both edged higher by 0.1%.
Oil majors Shell and BP rose about 1% each,tracking gains in crude prices on concerns that Iran's seizureof a British tanker last week may lead to supply disruptions inthe Middle East.
Monday's gains in the midcap bourse were led by Ted BakerPlc with a 13.5% jump, after a media report that itsfounder Ray Kelvin could back a private equity buyout of theretailer, months after he resigned.
Tour operator TUI's London-listed shares rose 4.6%,topping the FTSE 100 leader-board after Stifel resumed coverageon the stock with a "buy" rating.
Just Eat added 2.3% after the online takeaway servicesaid it would lay off "a number" of jobs in Britain as itcombined its customer and restaurant operations.
Helped in part by expectations of interest rate cuts bycentral banks, the exporter-heavy FTSE 100 has recovered from aslump it had weathered in May due to global trade uncertainty,and is currently on course for its best year since 2016.
The index, whose components roughly two-thirds of profits inthe U.S. dollar, has also benefited as Brexit jitters havepressured the pound.
According to polls and bookmakers, Boris Johnson will becomeBritain's new prime minister on Wednesday and will immediatelyface the riddle that is Britain's Brexit negotiation.
"Watch for a harder tone on Brexit and the very clearmessage that October 31st is a hard date. As previously argued,the reality of parliamentary arithmetic may see this soften indue course," Markets.com analyst Neil Wilson said.
Metro Bank advanced 6% after the troubled mid-caplender confirmed a report that it was in talks on the sale of aloan portfolio.
The stock has plummeted 70% so far this year as anaccounting error, which eventually led to a cash call and awarning on results, has spooked investors.
Weighing on the main index was Whitbread, which lost4.4% after the company said it was not planning any furthercapital return to shareholders.
Among smaller stocks, Petra Diamonds tumbled 9%after it reported full-year revenue below analysts' estimatesand said it expects next year's production to be slightly loweramid weak demand in the diamond market.(Reporting by Muvija M, additional reporting by ShashwatAwasthi and Samantha Machado in BengaluruEditing by Shounak Dasgupta and Frances Kerry)
