DUBAI - Qatar's stock index was down again on Monday as shares in Qatar Insurance tumbled after it announced the closure of its Abu Dhabi branch because of the region's diplomatic crisis.

The stock index had fallen for the previous 10 straight sessions.

Qatar Insurance dropped 4.6 percent after the company said its licence to operate in Abu Dhabi had not been renewed. Its Abu Dhabi unit, which had been operating since 2002, used to bring in annual revenue of 110 million Qatari riyals ($30 mln), the company said.

The news dealt another blow to Qatari shares, sending 14 other large-caps lower and taking the main index down 1 percent. As of Sunday, the index had dropped 15.6 percent since Saudi Arabia and other Arab states cut diplomatic and transport ties with Doha in early June.

"The market is in free-fall at the moment and until there is clarity about how the crisis will be resolved, I don't see a floor," said a regional fund manager.

The Saudi index barely moved in the first 40 minutes of trade, with some of the petrochemical and banking shares that had risen on Sunday reversing slightly on profit taking. Yanbu National Petrochemical fell 0.3 percent and Alawwal Bank lost 0.8 percent.

In the United Arab Emirates, the Dubai index was up 0.3 percent as Emaar Properties rose 1.5 percent and Dubai Islamic Bank added 0.7 percent. Abu Dhabi's index was flat.

(Reporting by Celine Aswad; Editing by Andrew Torchia and Susan Fenton) ((celine.aswad@thomsonreuters.com)(+9715 62247653)(Reuters Messaging: celine.aswad.thomsonreuters.com@reuters.net))