Major Gulf stock markets ended mixed on Sunday with Saudi Arabian shares extending gains for a sixth consecutive day, while Dubai fell after five days of rises.

All major Gulf stocks registered gains in the week to Thursday, riding on a rally fuelled by optimism around COVID-19 vaccine developments.

Saudi Arabia's main index was up 0.2% as Dr. Sulaiman Al-Habib Medical Services Group surged 8.7%, its sharpest intra-day rise since July and registering third straight gains.

The healthcare firm will be included in the MSCI Global Standard Index, as of Nov. 30, the MSCI semi-annual index review shows.

Saudi Electricity advanced 3% in its fifth daily rise in six trading days.

Moody's on Wednesday upgraded the utility company's rating to A1, citing increased government support. The company recently signed an agreement with the government to convert state liabilities worth 167.92 billion riyals ($45 billion) into a subordinated perpetual financial instrument.

Elsewhere, Saudi Pharmaceutical Industries & Medical Appliances Corporation 2070.SE jumped 5.5%. The company said it signed a memorandum of understanding with German biopharmaceutical company Curevac to supply and distribute a COVID-19 vaccine. 

Dubai's index fell 0.8%, ending a winning streak of five consecutive sessions.

Emirates NBD Bank dropped 1.9%, while Emaar Malls declined 3.1%.

Abu Dhabi's index was up 0.3% with Emirates Telecommunications Group rising 1.3% and International Holdings Company gaining 0.7%

The Qatari index edged down 0.1% with most of its constituents closing in the red. Qatar Gas Transport led the losers, declining 2.1%.

Losses were partially offset by Industries Qatar  which rose 2%.

Outside the Gulf, the Egyptian blue-chip index  traded up 0.3%. Commercial International Bank Egypt edged up 0.2% and tobacco firm Eastern Company added 1.1%.

El Sewedy Electric, however, dipped 0.7% as its third-quarter net profit fell to 817.5 million pounds ($52.37 million) from 829 million pounds a year earlier. 

($1 = 15.6100 Egyptian pounds)

(Reporting by Maqsood Alam in Bengaluru; editing by Emelia Sithole-Matarise) ((Maqsood.Alam@thomsonreuters.com;))