DUBAI - Most Gulf stock markets were narrowly mixed in early trade on Tuesday with Saudi Arabia edging up for a fifth straight day as it was boosted by the petrochemical sector.

The Saudi index rose 0.1 percent in the first hour as Chemanol gained 1.2 percent and PetroRabigh added 0.4 percent.

In Qatar, the main index fell 0.3 percent despite a 0.5 percent gain by Qatar National Bank, the region's largest bank by assets.

Qatari Investors Group, a conglomerate which last week traded at its lowest level since 2013 and has been rebounding sharply in heavy trade since then, added 1.2 percent.

Dubai's index fell 0.5 percent as Emaar Properties slipped 1.0 percent. But Drake & Scull rose 2.3 percent in heavy trade; it announced on Monday that its shares had been included in the MSCI GCC index.

In Abu Dhabi, the index edged down 0.1 percent as Manazel Real Estate, the most heavily traded stock, fell back 1.8 percent. It had risen earlier this week when it said plans were underway to expand into Middle East and North African markets.

(Reporting by Aziz El Yaakoubi; Editing by Andrew Torchia/Jeremy Gaunt) ((aziz.elyaakoubi@thomsonreuters.com; +971552994086))