* TSX ends down 13.70 points or 0.1 pct, at 14,000
* Four of TSX's 10 main groups lower
* Energy stocks down 0.5 pct, materials off 0.4 pct (Updates to close, adds details, quotes)
By Claire Sibonney
TORONTO, March 22 (Reuters) - Toronto's main stock index ended slightly lower on Tuesday, after a three-day rise, as weighty commodity issues gave back some recent gains and many traders kept to the sidelines amid political uncertainty overseas and at home.
The energy sector was down 0.5 percent after finishing up 1.61 percent on Monday, while the materials group, home to mining companies, was down 0.4 percent -- despite higher prices for oil and base metals.
Canadian Natural Resources (CNQ.TO) slid 0.6 percent to C$48.44, while Canadian Oil Sands COS.TO fell 1.7 percent to C$31.49.
Fertilizer giant Potash Corp (POT.TO) was down 1.3 percent at C$53.97 and Teck Resources TCKb.TO shed 1.5 percent to C$52.07.
"Stock markets here and south of the border are actually fairly quiet today. We've had a little bit of action here the last couple days, and yesterday we had a nice up day," said John Kurgan, senior market strategist at Lind-Waldock Canada.
"Pretty much market makers on the floor and investors in general just kind of sitting on their hands, waiting," he added noting lighter than average volumes.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE ended down 13.70 points or 0.1 percent, at 14,000, giving back some of Monday's 1.62 percent gain.
Four of the TSX's 10 main groups were lower. Financial stocks helped cushion the decline, rising 0.2 percent. Bank of Nova Scotia (BNS.TO) was up 1 percent at C$59.21.
Gold-mining shares were also firmer, rising 0.5 percent, with Agnico Eagle (AEM.TO) up 0.6 percent at C$66.23.
Events in Canada and overseas continued to weigh on market sentiment and kept many investors playing wait-and-see.
U.S. President Barack Obama won British and French support for a NATO role in the air campaign against Libya's Muammar Gaddafi as coalition forces thrashed out operational details aimed at transferring U.S. control of the mission. [ID:nN22512993]
Meanwhile, Japan continued to battle a quake-crippled nuclear plant as radiation fears grew. [ID:nL3E7EL23A]
In domestic politics, the minority Conservative government presented its budget after the market closed at 4 p.m. (2000 GMT), pledging to slice the deficit by a quarter this year and return to surplus in 2015.
The budget offered a host of treats to opposition parties in the hope of winning their support and avoiding an election. [ID:nCFB004022]
($1=$0.98 Canadian) (Additional reporting by Solarina Ho; editing by Rob Wilson)