Oil and gas stocks fell on Tuesday after the International Energy Agency (IEA) said global oil demand would increase by less than initially estimated this year. The IEA said that despite heightened geopolitical tensions in countries such as Libya, Iraq and Ukraine, "the oil market today looks better supplied than expected, with an oil glut even reported in the Atlantic basin".Even the latest round of Western sanctions on Russia's oil sector will not have a tangible near-term impact on supplies, it said.The IEA said that global oil demand would rise by 1m barrels a day this year, down 180,000 barrels a day from its previous forecast on the back of weaker-than-expected demand in the second quarter.The estimates sent the price of Brent crude down 1.2% to $103.45 a barrel in afternoon trade in London.Royal Dutch Shell was among the worst performers in the UK oil sector, down 1.3%, on the news that it is set to cut around 250 jobs at its onshore North Sea oil operations in Aberdeen. Ophir Energy, BP, Tullow and Genel Energy were also registering losses.Top performing sectors so far todayIndustrial Transportation 2,779.09 +0.86%Health Care Equipment & Services 5,701.39 +0.75%Electronic & Electrical Equipment 3,792.17 +0.67%Banks 4,431.34 +0.66%Life Insurance 7,078.55 +0.49%Bottom performing sectors so far todayForestry & Paper 10,879.07 -1.46%Chemicals 9,941.86 -1.08%Oil Equipment, Services & Distribution 22,780.95 -0.94%Industrial Metals & Mining 1,212.19 -0.93%Oil & Gas Producers 8,283.01 -0.77%BC