* Wells Fargo profit flat as costs, mortgages weigh
* S&P tech sector looks to snap nine-day losing streak
* Indexes down: Dow 0.33 pct, S&P 0.29 pct, Nasdaq 0.13 pct (Updates to late afternoon)
By Lewis Krauskopf
April 13 (Reuters) - Wall Street fell on Thursday and looked set to book losses for a third straight day as investors weighed earnings from big U.S. banks and geopolitical tensions.
Wells Fargo shares fell 2.4 percent, pulling down the S&P 500, after the bank reported a drop in mortgage banking revenue. Berkshire Hathaway also disclosed late on Wednesday that it had cut its stake in the bank.
JPMorgan and Citigroup also slipped about 0.5 percent each, despite reporting better-than-expected quarterly profits.
Investors have sought safe-haven assets throughout the week due to geopolitical tensions in Syria and North Korea. News of a massive bomb being dropped by the United States in eastern Afghanistan on Thursday added to uncertainty.
Kate Warne, principal investment strategist at Edward Jones in St. Louis, said a dip in bond yields put pressure on stocks ahead of a holiday weekend in the United States.
"What we've seen is investors from the rest of the world putting more money in U.S. Treasuries" due to geopolitical concerns, Warne said.
The Dow Jones Industrial Average fell 67.02 points, or 0.33 percent, to 20,524.84, the S&P 500 lost 6.78 points, or 0.29 percent, to 2,338.15 and the Nasdaq Composite dropped 7.46 points, or 0.13 percent, to 5,828.70.
Bank stocks had helped drive the overall market higher after U.S. President Donald Trump's Nov. 8 election victory, but the rally has stalled as U.S. bond yields have declined and investors question Trump's ability to enact his agenda including tax cuts and economic stimulus.
The S&P 500 financial index slipped 0.7 percent, setting it up for a fifth straight day of losses.
Energy shares were the worst-performing group, falling 1.3 percent.
The technology sector was little changed after nine straight sessions of losses.
Reports from banks kicked off what is expected to be a strong first-quarter U.S. reporting season. S&P 500 companies are expected to post a 10.4 percent rise in earnings for the period, according to Thomson Reuters I/B/E/S.
"We could have double-digit earnings growth; we haven’t seen that in some time," said Karyn Cavanaugh, senior market strategist at Voya Investment Management in New York. "Investors are going to be impressed with that."
A report from the University of Michigan showed that U.S. consumer sentiment unexpectedly strengthened in April as consumer optimism on current economic conditions climbed to its highest level since November 2000.
Declining issues outnumbered advancing ones on the NYSE by a 2.01-to-1 ratio; on Nasdaq, a 1.77-to-1 ratio favored decliners.
The S&P 500 posted 7 new 52-week highs and 1 new low; the Nasdaq Composite recorded 25 new highs and 48 new lows. (Additional reporting by Sinead Carew in New York and Yashaswini Swamynathan in Bengaluru; Editing by Anil D'Silva and Meredith Mazzilli)