(Adds comments, updates market action after Iran deal)
* TSX up 0.59 points, or 0 percent, at 14,533.81
* Six of the TSX's 10 main groups lower
By Solarina Ho
TORONTO, July 14 (Reuters) - Canada's main stock index was little changed on Tuesday as oil and gas stocks unexpectedly gained despite a long-awaited nuclear deal between six world powers and Iran that will put more Iranian oil on an already oversupplied market.
Market expectations that the landmark agreement will not add much oil to the market until well into next year resulted in crude prices sharply paring back early losses spurred by the deal.
"We finally get this deal with Iran that could bring more supply in and energy stocks go up," said Julie Brough, vice president at Morgan Meighen & Associates, who speculated that investors were perhaps selling on the rumor and buying on the news.
"Maybe the deal was going to not bring in as much supply as soon as people thought it might ... Some days, things don't go the way you think they will."
U.S. crude prices were up 0.1 percent at $52.24 a barrel, while Brent crude was down 0.5 percent at $57.56.
At 11:30 a.m. EDT (1530 GMT), the Toronto Stock Exchange's S&P/TSX composite index was up 0.59 points, or 0 percent, at 14,533.81. Of the index's 10 main groups, half were in positive territory.
"Outside of that, it's kind of a non-eventful day," Brough said. "I think there's this overhang of caution."
She noted the arrival of earnings season and expectations that it will likely be a weak one given Canada's lackluster economic growth.
The most influential decliners on the index included Toronto-Dominion Bank, which fell 0.86 percent to C$51.93, and Royal Bank of Canada, which declined 0.8 percent to C$76.34.
The overall financials sector, home to banks and insurers, retreated 0.7 percent.
Seven of the 10 biggest boosts to the index belonged to the oil and gas group. Encana Corp rose 2.5 percent to C$12.53 and Suncor Energy Inc added 0.3 percent to C$34.49.
Advancing issues outnumbered declining ones on the TSX by 144 to 97, for a 1.48-to-1 ratio on the upside.
$1=$1.27 Canadian Reporting by Solarina Ho; Editing by Peter Galloway