* Google shares dip, executive to sell nearly half his stake
* Fed's Yellen says Fed taking 'forceful action' on economy
* Dow off 0.2 pct; S&P off 0.1 pct; Nasdaq off 0.2 pct
By Angela Moon
NEW YORK, Feb 11 (Reuters) - U.S. stocks slipped on Monday on lack of catalysts to move the market higher after a six-weeks-long advance that has taken the S&P 500 index near record highs.
The benchmark index is up more than 6 percent so far this year after a steep rally in January that has stalled as the S&P and Dow industrials near multiyear highs.
Google Inc shares fell 1 percent at $777.67 after the company said in a filing former chief executive Eric Schmidt is selling roughly 42 percent of his Google stake, a move that could potentially net him $2.51 billion.
But the decline was offset by gains in Apple, up 1.4 percent at $481.73 after a New York Times report that the iPhone maker is experimenting with the design of a device similar to a wristwatch.
"It's really the valuation and indications that the economy is improving that have pushed the market higher. We would have to see a probable correction before heading higher and that could come from weak economic data in the future," said Tim Ghriskey, chief investment officer at Solaris Asset Management.
The Federal Reserve's Vice Chair Janet Yellen, seen as a potential successor to Fed Chairman Ben Bernanke next year, said the Fed is still aggressively stimulating an anemic U.S. economic recovery that has failed to bring rapid progress on employment.
On Tuesday, President Barack Obama will describe his plan for spurring the economy in his State of the Union address. He is expected to offer proposals for investment in infrastructure, manufacturing, clean energy and education.
The Dow Jones industrial average was down 24.96 points, or 0.18 percent, at 13,968.01. The Standard & Poor's 500 Index was down 1.56 points, or 0.10 percent, at 1,516.37. The Nasdaq Composite Index was down 5.00 points, or 0.16 percent, at 3,188.93.
Upbeat U.S. and Chinese data last week helped the S&P 500 extend its weekly winning streak to six.
Opposition has grown to the $24.4 billion buyout of Dell Inc , the No. 3 personal computer maker, as three of the largest investors joined Southeastern Asset Management on Friday in raising objections. Dell said in a regulatory filing it had considered many strategic options before opting to go private in a buyout led by Chief Executive Michael Dell.
Dell shares hovered near $13.65, the buyout offer price.
Regeneron Pharmaceuticals Inc shares rose 1.6 percent at $168.72 after it said longtime drug development partner Sanofi plans to boost its stake in Regeneron by open market purchases of its stock.