Oman's index rose to an 11-week high while UAE markets traded sideways with little in the form of catalysts to boost sentiment.
Muscat's benchmark rose 0.4 percent to 5,625 points, its highest level since Sept 28.
The market rallied for an eighth straight session and analysts say strong valuations and dividend-yield is drawing investors.
"Local funds started to buy at these levels and a lot of speculators are also trading now because our market has fallen a lot year-to-date" said Alaa El Din Moustafa, Oman-based chief dealer at EFG-Hermes.
The index is still down 16.7 percent so far in 2011. Galfar Engineering gained 2 percent, accounting for more than half the shares traded.
Bank Muscat climbed 0.7 percent and Renaissance Services rose 0.7 percent.
Elsewhere, Dubai's index traded near-flat while Abu Dhabi's benchmark slipped 0.2 percent to 2,454 points.
State-run Abu Dhabi National Energy Co (TAQA) on Monday sold $1.5bn in bonds maturing in five and 10 years to refinance upcoming debt.
The stock was down 0.8 percent.
Kuwait's index slipped 0.1 percent to 5,847 points, as investors await an election date for a new government.