* Banks rebound from recent losses
* Alphabet falls after YouTube ad row; top drag on S&P, Nasdaq
* Accenture falls after quarterly profit slips
* Indexes: Dow +0.08 pct, S&P +0.03 pct, Nasdaq -0.01 pct (Updates to afternoon)
By Noel Randewich
March 23 (Reuters) - Wall Street wavered on Thursday as investors snapped up beaten-down bank stocks and fretted about a vote on a healthcare bill that is seen as President Donald Trump's first policy test.
The House vote had been expected by about 7 p.m. ET (2300 GMT) but there were signs the deadline could be pushed back because of a lack of support from Republican lawmakers.
Failure to pass the American Health Care Act would cast doubt on Trump's ability to deliver other parts of his agenda that need the cooperation of the Republican-controlled Congress, including ambitious plans to overhaul the tax code and invest in infrastructure.
"Today's action is basically speculation about whether the House is going to pass this healthcare bill," said Bruce Bittles, chief investment strategist at Robert W. Baird.
But Bittles predicted that, even if the bill fails, any selloff in stocks will be short-lived as investors who have missed out on a rally since November jump into the market.
The S&P 500 has gained 10 percent since the election, spurred mainly by Trump's campaign promises to enact legislation seen as pro-business.
The benchmark index is trading at about 18 times expected forward earnings, compared with a 10-year average of 14, according to Thomson Reuters data.
The Dow Jones Industrial Average was up 0.08 percent at 20,677.73 points, while the S&P 500 had gained 0.03 percent to 2,349.1.
The Nasdaq Composite dropped 0.01 percent to 5,820.79. Eight of the 11 major S&P indexes were higher, with the financial index's 0.76-percent rise among the top performers. The sector, which had its worst one-day fall since June on Tuesday, has risen the most since the election.
Bank of America's 1.24-percent rise lifted the S&P 500, while Goldman Sachs' 0.72-percent increase helped push the Dow higher.
Google-parent Alphabet fell 1.32 percent as more firms pull YouTube ads on fears they may appear alongside offensive videos. The stock was the biggest drag on the S&P 500 and the Nasdaq.
Five Below surged 11.74 percent after the retailer's quarterly earnings beat estimates.
Accenture fell 4.49 percent after the consulting and outsourcing services provider's quarterly profit slipped.
Advancing issues outnumbered declining ones on the NYSE by a 2.91-to-1 ratio; on Nasdaq, a 2.20-to-1 ratio favored advancers.
The S&P 500 posted 14 new 52-week highs and 1 new lows; the Nasdaq Composite recorded 44 new highs and 37 new lows. (Additional reporting by Tanya Agrawal in Bengaluru; Editing by Nick Zieminski)