DUBAI  - Qatar's stock market kept rising sharply early on Tuesday after two top companies said they were raising their ceilings for foreign ownership, while other Gulf markets were much more subdued.

The Qatari stock index, which had soared 5.0 percent on Monday, added a further 2.1 percent. Qatar National Bank, which had risen its 10-percent daily limit on Monday, climbed 7.0 percent. The bank said on Monday that it would recommend to shareholders increasing its non-Qatari ownership ceiling to 49 percent of capital from 25 percent, a step which would increase its weighting in emerging market equity indexes, attracting fresh flows of foreign funds.

Industries Qatar gained 5.9 percent on Tuesday morning after leaping 10 percent on Monday. On Tuesday, the company said it had increased its foreign ownership limit to 49 percent from 25 percent.

In Saudi Arabia, the index rose 0.6 percent in the first half-hour, building on its technical breakout on Monday, when it surpassed its January peak to close at its highest level since October 2015.

Sahara Petrochemical climbed 2.1 percent and Sipchem surged 4.3 percent after Sipchem said it planned to resume merger talks with Sahara. The two companies called off a planned merger in 2014, citing an inadequate regulatory framework in the country.

Dubai's index slid 0.3 percent as Emirates NBD fell back 1.0 percent. The company had soared 19 percent in the past two days after saying it planned a big capital increase, which analysts think will mean raising its 5 percent ceiling for foreign ownership.

(Editing by Andrew Heavens) ((andrew.torchia@thomsonreuters.com; +9715 6681 7277; Reuters Messaging: andrew.torchia.thomsonreuters.com@reuters.net))