Saudi Arabia's petrochemicals helped the index make small gains and insurance stocks supported but banks slipped for a second day.
The benchmark was up 0.07 percent to 6,140 points, trading in a sideways trend.
Saudi Basic Industries Corp (SABIC) rose 0.3 percent and Rabigh Refining and Petrochemical Co gained 0.4 percent.
Gains in oil support after Brent crude futures and its US counterpart rose $1 on Monday on hopes European policymakers would reach an agreement to tackle the eurozone's debt crisis and help stem a slowdown in oil demand growth.
The insurance index climbed 1.2 percent.
Banks fell with Samba Financial Group down 0.7 percent, booking profit from Sunday's gains after reporting a 2.9 percent increase in quarterly profit.
Banque Saudi Fransi shed 0.3 percent.
Some analysts say the sector's numbers so far on a quarterly basis have disappointed due to higher provisioning.
"Provisioning may be higher because of three things - loans have grown so provisioning also tends to move up with volumes," said Asim Bukhtiar, head of research at Riyad Capital.
"Provisions in H1 were too little, so banks are trying to make up for that and there may be exposure to Europe and North America."
Saudi Arabian Mining Co (Maaden) gained 0.4 percent after saying it signed with 13 local and international banks a SR3.7bn ($991.5m) facility for the second phase of its aluminum project.
Kuwait's National Industries Group Holding (NIG) fell after saying it was looking to sell its stake in Mabanee Real Estate Co, weighing on the index.
Shares in the unit of family-owned Kharafi Group fell 1.9 percent and Mabanee traded flat.
Logistics firm Agility slipped 2.6 percent as investors booked profits. The stock hit a five-month high on Thursday on speculation about a contract. On Tuesday, the firm denied reports that it had won a military contract worth up to $700m, sending its shares lower.
The benchmark fell 0.1 percent to 5,892 points, down from Sunday's three-week high.
In Qatar, the index edged up 0.1 percent to 8,450 points, but was still down 2.7 percent on the year.
"Although banks results were strong - but we didn't see the market respond," said Mohammed Yasin, CAPM Investment chief investment officer. "We don't have a catalyst to change the direction."
Heavyweight Qatar National Bank slipped 0.1 percent and Qatar Islamic Bank shed 0.3 percent.
Masraf Al Rayan climbed 0.2 percent ahead of expected third-quarter earnings.
Property stocks in Abu Dhabi weighed on the UAE capital's index which slipped to a fresh 22-month low, as global debt woes plagued sentiment in local markets.
Aldar Properties shed 2.9 percent and Sorouh Real Estate fell 2.1 percent. Dana Gas slipped 1.9 percent.
These stocks are the usual target of retail investors, trading for short-term gains, while also signaling thin institutional buyers.
The index eased 0.07 percent to 2,470 points.
In Dubai, the Dubai Islamic Bank supported the index with a 0.5 percent rise. Emirates NBD gained 1.4 percent.
The benchmark climbed 0.3 percent to 1,378 points, up from Sunday's seven-month lows.
Elsewhere, National Bank of Oman traded flat despite making an estimate-beating quarterly net profit of OMR10.2m, according to Reuters calculations.
"The stock continue to trade range bound; more on sentiment," said Kanaga Sundar, Gulf Baader Capital Markets head of research. "We may see buyers at these levels looking at a medium term horizon."
Bank Sohar and Bank Muscat rose 1.3 and 0.3 percent respectively but the index traded near-flat.
"With the stronger Q3 performance from banking sector majors, we expect the investors to accumulate positions at these values looking at a medium term horizon with valuations remaining attractive," he added.
Gulf markets are likely to trade sideways as investors wait for concrete actions from eurozone policy makers to solve the debt crisis.
Local markets took little comfort on Sunday from G20 finance chiefs at the weekend putting pressure on eurozone leaders to get on top of the two year old debt crisis, throwing attention on to what is now being seen as make-or-break European Union summit on October 23.
Sentiment may be lifted however, from a positive lead as Asian shares gain on Monday and the euro holds at a near one-month high.
"We saw positive markets last week because of developments on Europe - I think we still start to see some of that filter through to our markets but we're not out of the woods yet," said Tarek Lotfy, Arqaam Capital Head of MENA equities.