Saudi Arabia's stock market ended higher on Sunday buoyed by National Commercial Bank and Samba Financial Group after they signed an initial merger agreement, while Egypt's index extended losses.

The benchmark index in Saudi Arabia gained 0.8%, with Samba Financial Group rising 9.9% for its biggest intraday gain since June 2017, while National Commercial Bank (NCB) was up 5%.

NCB, the kingdom's biggest lender, said on Thursday it had signed an initial agreement with smaller lender Samba to create a combined entity with almost $214 billion in assets.

The offer would value each Samba share at 27.42 to 29.32 riyals ($7.82), giving it a maximum market value of $15.63 billion, 27.5% above its market value of nearly $12.3 billion based on Wednesday's closing price.

The two banks intend to conclude a reciprocal due diligence process and sign definitive agreements in relation to the proposed transaction within four months.

In Egypt, the index fell 0.4%, extending losses from the previous session, with most of its constituents lower. Commercial International Bank Egypt led the losers with a drop of 1.3%.

Dubai's main share index slipped 0.1%, hurt by a 0.7% dip in blue-chip developer Emaar Properties, but the index's fall was cushioned by a 4.2% jump in budget airliner Air Arabia.

In Abu Dhabi the index added 0.4%, with First Abu Dhabi Bank, the country's largest lender, gaining 1.5%.

The Qatari index dropped 0.6%, weighed down by a 1.1% decline in Qatar Islamic Bank and a 0.6% dip in the Gulf's largest lender Qatar National Bank.

Last week, Fitch Ratings said that Qatar's banks are at risk of volatile external funding conditions. 

($1 = 3.7508 riyals)

(Reporting by Ateeq Shariff in Bengaluru; Editing by Kirsten Donovan) ((AteeqUr.Shariff@thomsonreuters.com; +918061822788;))