DUBAI: Saudi Arabia's stock market rose on Sunday, boosted by National Commercial Bank and Samba Financial Group Bank after they signed an initial merger agreement, while Qatar's index retreated in early trade.

The benchmark index in Saudi Arabia rose 0.9%, with Samba Financial Group jumping 9.9% and National commercial Bank (NCB) up 5.2%.

NCB, the kingdom's biggest lender, said on Thursday it had signed an initial agreement with smaller lender Samba Financial Group 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.

Qatar's index lost 0.5%, hurt by a 0.5% fall in Qatar Islamic Bank and a 1.4% drop in Industries Qatar.

Dubai added 0.5%, helped by a 1.1% rise in blue-chip developer Emaar Properties and a 0.8% gain in Dubai Islamic Bank. The Abu Dhabi index edged up 0.2% as the country's largest lender First ABu Dhabi Bank gained 0.9%.