UPDATE 2-FTSE 100 gains as sterling slips on renewed hard Brexit concerns

* FTSE 100 up 0.5%, FTSE 250 up 0.9%

* Exporter stocks gain after sterling slips

* Mid-cap FirstGroup hits near 2-yr high

* Daily Mail publisher surges on upbeat results

* De La Rue sinks to over 15-yr low after profit warning (Adds news item, analyst comment, updates to closing prices)

By Shashwat Awasthi

May 30 (Reuters) - London's top share index rose on Thursday as the pound slipped on concerns that outgoing Prime Minister Theresa May's successor might push for a hard Brexit, helping more internationally focused stocks gain.

The FTSE 100, whose components earn a large chunk of their revenue from outside the UK, rose 0.5%. The mid-cap FTSE 250 advanced 0.9%, bouncing back after steep losses in the previous session.

Internationally exposed stocks such as Diageo, Unilever and British American Tobacco were among the biggest boosts to the main index as mounting political worries sent sterling below $1.26 for the first time since a January 3 flash crash.

Britain's finance minister Philip Hammond warned his fellow party members vying for May's job that a no-deal Brexit would endanger the economy, as frontrunner Boris Johnson, considered a proponent of a hard Brexit, earned praise from U.S. President Donald Trump.

"What really compounds the pound's situation is that at this point it is hard to see June being any better, the month set to be consumed by a Brexit-focused Tory leadership battle," Spreadex analyst Connor Campbell said.

Investors also seemed to shed some aversion to risky assets through the day, even as the Sino-U.S. trade spat loomed large. China fired another shot at the United States on Thursday as Vice Foreign Minister Zhang Hanhui said provoking trade disputes was "naked economic terrorism."

Among blue-chip fallers was Johnson Matthey which shed 4.3% after the chemicals group's annual profit missed consensus estimates.

Energy utility National Grid and retailer Marks & Spencer slid more than 4.5% each as both stocks traded ex-dividend.

FirstGroup, under pressure from a shareholder to make strategic changes, gained 3.6% after jumping to a near two-year high, as it put its U.S. coach service Greyhound up for sale and also said it was looking to separate its UK First Bus operations.

"Greyhound is in long term structural decline and absorbs considerable management time without offering upside potential, and therefore disposing of it is optimal," Investec analysts wrote.

AVEVA climbed 6.7% higher as brokerages cast a bullish view on the stock after the industrial software company posted results on Thursday.

Among smaller stocks, De La Rue Plc lost a third of its value and plummeted to a more than 15-year low, after the banknote and passports maker issued a profit warning for fiscal 2020 and said its chief executive would step down.

But Daily Mail jumped almost 10% on the pan-regional STOXX 600 after it reported a better-than-expected rise in first-half profit and reaffirmed its annual forecasts. (Reporting by Shashwat Awasthi in Bengaluru; Editing by Alison Williams)