European shares seen opening sharply lower after Greek referendum

LONDON, July 6 (Reuters) - European shares headed for a sharp drop on Monday after Greeks rejected austerity measures demanded in return of a debt deal, raising concerns about the country's exit from the euro zone.

Financial spreadbetters predicted Britain's FTSE 100 to open 106 to 140 points lower, or down as much as 2.1 percent. Germany's DAX was seen falling 294 to 328 points, or as much as 3 percent lower, and France's CAC 40 was seen slipping by 134 to 143 points, or down as much as 3 percent.

Stunned European leaders called a summit for Tuesday to discuss their next move after the surprisingly strong victory by the 'No' camp defied opinion polls that had predicted a tight contest. German Chancellor Angela Merkel's deputy said Athens had wrecked any hope of compromise with its euro zone partners by overwhelmingly rejecting further austerity. (Reporting by Atul Prakash; Editing by Sudip Kar-Gupta)