(Reuters) - Britain's FTSE 250 slid on Thursday after Northern Ireland's Democratic Unionist Party (DUP) cast fresh doubts over the prospects of a Brexit deal, while shares of Grafton and rival building materials distributors were hammered after a profit warning.
The FTSE 250 <.FTMC>, up more than 3% since last week amid a flurry of contrasting Brexit headlines, shed 0.5% after the DUP, which supports Boris Johnson's minority government, said it could not back the Brexit deal as it currently stands.
Shares of Grafton <GFTU_u.L> slid 10% after it warned on its annual profit, while peers Travis Perkins <TPK.L>, Howden Joinery <HWDN.L> and SIG <SHI.L> gave up between 2.3% and 6%.
The FTSE 100 <.FTSE> edged 0.1% higher by 0714 GMT, helped by gains in Unilever <ULVR.L> after its quarterly update and as other exporter firms rose due to a weaker pound.
(Reporting by Shashwat Awasthi in Bengaluru; Editing by Shounak Dasgupta)
