UPDATE 3-Thermo Fisher 3rd-quarter profit edges higher

* Q3 adjusted EPS $0.78; estimate $0.75

* Revenue down 2 pct to $2.53 bln

* Sees full year adjusted EPS $2.95-$3.05

* Shares fall 2 pct (Adds analyst comment, share price)

NEW YORK, Oct 22 - Thermo Fisher Scientific Inc reported on Thursday that third-quarter profit edged higher, topping Wall Street expectations, as lower costs helped offset a decline in revenue.

But the company narrowed, rather than raised, its full-year earnings forecast and investors sent shares nearly 2 percent lower.

"The quarter was clearly a solid, clean quarter," said Cowen and Co analyst Doug Schenkel.

"I think what people are unhappy with is that after what looked like a better-than-expected Q3, the implied Q4 guidance isn't all that inspirational," Schenkel said, adding that it is unclear whether management was just being conservative or being prudent in a challenging environment.

The scientific instruments maker, still hurt by constrained customer spending, posted a net profit of $221.2 million, or 53 cents per share, up from $218.1 million, or 50 cents a share, a year ago.

Excluding one-time items, the Waltham, Massachusetts-based company earned 78 cents a share. Analysts on average expected 75 cents, according to Thomson Reuters I/B/E/S.

Revenue fell 2 percent to $2.53 billion, in line with Wall Street estimates of $2.51 billion.

The company, which slashed its 2009 earnings forecast in April and raised it slightly in July, adjusted it again on Thursday.

Thermo now expects full-year adjusted earnings of $2.95 to $3.05 per share, altering its prior view of $2.85 to $3.10. It now expects revenue of $9.95 billion to $10.05 billion, narrowing the range from its prior forecast of $9.8 billion to $10.1 billion.

"In line with our expectations, the economy continued to constrain our customers' spending on capital equipment, while sales of consumables showed increasing strength," Marc Casper, who succeeded longtime CEO Marijn Dekkers in mid-September, said in a statement.

Casper added that the company is "firmly on track to meet our financial goals for 2009."

Analytical Technologies sales fell 6 percent to $1.02 billion, while the Laboratory Products and Services unit saw sales edge 1 percent higher to $1.63 billion.

Total costs, including research and development and selling, general and administration expenses, were down 2 percent to $2.26 billion.

Thermo shares were down 90 cents or 2 percent at $46.41 on the New York Stock Exchange at midday.