* S&P 500 hits intraday record; Nasdaq climbs to 14-year high
* Insurance stocks rise after Humana comments
* Men's Wearhouse raises offer for Jos. A. Bank
* Dow up 0.6 pct; S&P 500 up 0.6 pct; Nasdaq up 0.7 pct
NEW YORK, Feb 24 (Reuters) - U.S. stocks rose on Monday and the S&P 500 hit a record intraday high, helped by gains in health insurers' shares and optimism about merger activity.
The Nasdaq reached a 14-year high, though all three indexes closed off their highs for the session. The S&P 500 finished less than a point away from its record closing high of 1,848.38.
Humana Inc and UnitedHealth Group ranked among the S&P 500's biggest percentage gainers, with Humana's stock jumping 10.6 percent to $113.69 after it said the government's proposed cuts to the private Medicare program appeared to be less than it had forecast. UnitedHealth shares rose 3 percent to $76.01.
Aetna Inc rose 2 percent to close at $71.80 after giving a 2014 earnings outlook.
Weak economic data has largely been blamed on harsh winter weather, which has kept investors hopeful that the economy's recovery remains intact. The latest data showed the Chicago Fed National Activity index fell to -0.39 in January from 0.16 in December while financial data firm Markit's preliminary February reading on the services sector fell to 52.7 from 56.7.
"There's still a lot of hope right now (that) the slightly weaker (economic) numbers we've been seeing are weather- related," said Bryant Evans, portfolio manager at Cozad Asset Management in Champaign, Illinois.
The Dow Jones industrial average rose 103.84 points or 0.64 percent, to close at 16,207.14. The S&P 500 gained 11.36 points or 0.62 percent, to end at 1,847.61, after rising to an intraday record of 1,858.71.
The Nasdaq Composite added 29.558 points or 0.69 percent, to finish at 4,292.968.
The S&P 500 broke above resistance at 1,841, which propelled further gains, said Mark Luschini, chief investment strategist at Janney Montgomery Scott in Philadelphia.
The Dow Jones Transportation Average, whose components include package-shipping companies like FedEx and United Parcel Service, rose 0.4 percent.
In the deal arena, chipmaker RF Micro Devices Inc agreed to buy TriQuint Semiconductor Inc for about $1.6 billion. Men's Wearhouse Inc raised its cash tender offer for rival men's clothing retailer Jos. A. Bank Clothiers Inc to $63.50 per share from $57.50.
Shares of RF Micro shot up 21 percent to $7.03 while TriQuint's stock surged 26.1 percent to $11.64.
Men's Wearhouse shares jumped 7.5 percent to $48.51 while Jos. A. Bank's stock soared 9.1 percent to close at $60.04.
Helping lift the Nasdaq, shares of eBay rose 3.1 percent to $56.30 as billionaire investor Carl Icahn called again for the spinoff of eBay's fast-growing PayPal payments business.
Adding some support was news that Ukrainian President Viktor Yanukovich was ousted. While that leaves a potential power vacuum and an ailing economy, it calmed some worries.
Many traders are looking ahead to Thursday, when Federal Reserve Chair Janet Yellen will speak to the Senate Banking Committee in her semi-annual testimony about monetary policy.
Yellen's comments will be scoured for insight into the extent to which bad weather has affected economic activity, as well as for confirmation that the Fed will not make any changes to its schedule for trimming stimulus.
After the bell, shares of Tenet Healthcare declined 3.8 percent to $46.50 following the release of its results.
About 7.1 billion shares changed hands on U.S. exchanges, just above the 7 billion average so far this month, according to data from BATS Global Markets.
Advancers beat decliners on the New York Stock Exchange by a ratio of about 1.6 to 1 and on the Nasdaq by about 1.8 to 1.