* U.S. dollar advance weighs on broader market
* Tech clings to slight gains after RIM, Oracle results
* Dow up 0.2 pct; S&P 500 up 0.6 pct; Nasdaq up 1.5 pct
* For up-to-the-minute market news, click STXNEWS/US (Updates to close, changes byline)
By Chuck Mikolajczak
NEW YORK, Dec 18 (Reuters) - U.S. stocks rose on Friday in choppy trade as quarterly results from Oracle and Research In Motion lifted the Nasdaq more than 1 percent, but the U.S. dollar's climb curbed gains in both the Dow and the S&P 500.
The Nasdaq was led higher by Oracle Corp <ORCL.O> shares, which jumped 6.4 percent to $24.34, and the U.S.-listed stock of Research In Motion Inc <RIMM.O><RIM.TO>, which surged 10.3 percent to $69.99. For details see [
] and [ ]Despite the lift from these earnings-related stories, the robust dollar sapped much of the broader market's strength.
The U.S. dollar index <.DXY> climbed as much as 0.6 percent, but pared gains late in the session, easing some of the selling pressure on stocks. For the day, the U.S. dollar index ended just marginally higher -- up 0.03 percent.
Shares of multinational companies suffered from the greenback's rise. Heavy equipment maker Caterpillar Inc <CAT.N> fell 0.6 percent to $57.19, while plane maker Boeing Co <BA.N> was the biggest drag on the Dow, off 1.9 percent at $53.44.
Geopolitical concerns supported the flight to the U.S. dollar following reports that Iranian troops had entered Iraqi territory and raised the Iranian flag at an oilfield whose ownership is disputed by Iran.
"If there is tension developing in the Middle East, that would positive for the dollar because that would bring flight to safety ... that, in turn, could be negative for the equities markets," said Paul Mendelsohn, chief investment strategist at Windham Financial Services in Charlotte, Vermont.
A strong U.S. dollar forces investors who have bet on a decline in the greenback to cover their short dollar positions by selling equities or other assets.
The Dow Jones industrial average <
> added 20.63 points, or 0.20 percent, to 10,328.89. The Standard & Poor's 500 Index <.SPX> gained 6.39 points, or 0.58 percent, to 1,102.47. The Nasdaq Composite Index < > climbed 31.64 points, or 1.45 percent, to 2,211.69.For the week, the the Dow fell 1.3 percent, the S&P shed 0.3 percent and the Nasdaq rose 1 percent.
The declines snapped a two-week winning streak for the Dow and a three-week series of gains for the S&P 500.
Trading was choppy as Friday marked the expiration of December options and futures, a convergence known as quadruple witching that often means increased volatility as big investors adjust or exercise derivatives positions.
In addition the market was set to see an adjustment to the S&P 500. Visa Inc <V.N>, up 2.2 percent at $88.97, is among companies that will be the newest additions to the benchmark index after the close.
Volume was extremely heavy on the New York Stock Exchange, with 3.16 billion shares changing hands -- more than double last year's estimated daily average of 1.49 billion. On the Nasdaq, about 2.86 billion shares traded, well above last year's daily average of 2.28 billion.
Advancing stocks outnumbered declining ones on the NYSE by a ratio of 3 to 2, while on the Nasdaq, 16 stocks rose for every 11 that fell. (Editing by Jan Paschal)