DUBAI - Most Gulf stock markets were soft in early trade on Thursday as several companies in Dubai, Abu Dhabi and Qatar went ex-dividend, while Saudi Arabia continued to climb on optimism over its entry into emerging market indexes.

The Saudi index rose 0.8 percent in the first hour, anticipating FTSE's decision at the end of March on whether to upgrade Riyadh to secondary emerging market status.

The biggest market movers included petrochemical firm Saudi Basic Industries Corp and Saudi Telecom, up 2.0 percent and 4.0 percent respectively - stocks that are expected to figure prominently in the global indexes.

"FTSE is the main catalyst driving investors into the market," said Marie Salem, director of capital markets at FFA Dubai.

Saudi exchange data showed foreign investors bought a net $367 million of stocks in the week through March 15, the highest weekly total on record.

Many smaller stocks were disregarded by investors, including real estate investment trusts, which saw little activity. Al Rajhi REIT, which has been sinking since it listed on Tuesday, fell a further 1.9 percent to 9.15 riyals. It raised 427 million riyals in its initial public offer by selling units at 10 riyals each.

The Abu Dhabi index edged down 0.1 percent with Abu Dhabi Commercial Bank down 5.2 percent as it went ex-dividend.

Air Arabia was down 8.5 percent in Dubai as it too went ex-dividend, pulling the index 1.1 percent lower.

Emaar Properties, which rose on Wednesday after signing a joint venture agreement with Abu Dhabi's Aldar Properties to develop local and international projects, dropped back 3.1 percent.

"People are a bit reluctant to hold positions over the weekend," said Salem.

Qatar's index was down 0.4 percent. Big movers United Development, which fell 6.8 percent, and Commercial Bank, which lost 3.4 percent, both went ex-dividend.

(Reporting by Katie Paul; Editing by Andrew Torchia) ((Katie.Paul@thomsonreuters.com;))