DUBAI, June 26 (Reuters) - Saudi Arabia's stock market fell sharply at the opening on Sunday in response to Britain's decision to leave the European Union, but blue chips held up relatively well and the biggest losses were in smaller speculative stocks favoured by local retail investors.
The main index was down 3.7 percent after five minutes of trade. Among speculative stocks, Saudi Fisheries tumbled 6.2 percent.
But petrochemical blue chip Saudi Basic Industries fell only 2.4 percent and National Commercial Bank was down 2.8 percent, suggesting institutional investors, who focus on such stocks, were not selling as heavily.
Arabian Pipes , which soared last week after winning a contract from oil giant Saudi Aramco, stayed firm and gained 3.0 percent.
(Reporting by Andrew Torchia) ((firstname.lastname@example.org; +9715 6681 7277; Reuters Messaging: email@example.com))