* S&P, Dow set for four weeks of gains in a row
* Oracle dips after bleak forecast for cloud business
* Indexes up: Dow 0.51 pct, S&P 500 0.65 pct, Nasdaq 0.57 pct (Changes comment, adds details, updates prices)
By Rama Venkat Raman and Sruthi Shankar
Dec 15 (Reuters) - Wall Street indexes rose in morning trading on Friday, driven by gains in shares of banking and healthcare companies and on hopes that a final Republican tax bill will be unveiled in Congress later in the day.
The S&P financial index rose 1.07 percent, led by gains in JP Morgan and Citigroup stocks.
"People still think the tax bill will get done. I don't think Republicans are going to let this thing by the wayside, they've come this far," said Brent Schutte, chief investment strategist at Northwestern Mutual Wealth Management Company.
"Tax bill is moving the market in the short term, but the fundamentals that underlie that market, even without tax reform, are giving investors confidence."
Stocks have rallied this year, partly on hopes of corporate tax cuts that U.S. President Donald Trump promised during his election campaign. The bill, in its current form, proposes a corporate tax cut to 21 percent from 35 percent.
The S&P 500 fell the most in a month on Thursday after Republican Senators Marco Rubio and Mike Lee declined to back the bill without changes to child tax credits.
At 10:46 a.m. ET (1546 GMT), the Dow Jones Industrial Average was up 0.51 percent, at 24,634.57. The S&P 500 was up 0.65 percent, at 2,669.38 and the Nasdaq Composite was up 0.57 percent, at 6,895.36.
Costco rose 4.5 percent after the retailer reported upbeat results and pushed up the S&P Consumer Staples index by 1.15 percent.
The S&P 500 and the Dow were on track to record four weeks of gains in a row, while the Nasdaq was set to post its first rise in three weeks.
Healthcare stocks such as Pfizer, Medtronic, Thermo Fisher, Express Scripts and Abbvie rose between 3.33 percent and 1.03 percent.
Oracle's shares slipped 5.6 percent after the company's forecast for the current-quarter cloud revenue growth missed estimates and the second quarter sales in the business disappointed.
CSX Corp fell about 7.5 percent after the No.3 U.S. railroad said its Chief Executive Hunter Harrison was taking medical leave, a decision that comes in the middle of a controversial turnaround plan.
Advancing issues outnumbered decliners on the NYSE by 2,065 to 729. On the Nasdaq, 1,943 issues rose and 816. (Reporting by Rama Venkat Raman and Sruthi Shankar in Bengaluru; Editing by Arun Koyyur)