NEW YORK, April 28 (Reuters) - Covance Inc (CVD.N: Quote, Profile, Research), which conducts clinical testing for pharmaceutical companies, on Monday reported first-quarter profit rose 26 percent on double-digit growth in its early- and late-stage drug development services.

The Princeton, New Jersey-based company posted a net profit of $49.1 million, or 76 cents per share, compared with a profit of $38.9 million, or 60 cents per share, a year ago.

Excluding a one-time gain on the sale of a business, Covance earned 73 cents per share, matching analysts' average expectations, according to Reuters Estimates.

Revenue for the quarter rose 15 percent to $434 million, topping Wall Street estimates of $415.6 million.

Early development sales rose 12.7 percent to $202 million, while late-stage development revenue grew 17.5 percent to $210.4 million.

As large drug companies engage in aggressive cost cutting, more and more of their clinical trials work is being outsourced to companies such as Covance.

Citing "favorable market conditions" Covance said it expected to deliver low- to mid-teens revenue growth and full-year earnings of $3.18 per share, representing 20 percent annual growth.

Analysts are estimating $3.18 per share for the year.

Covance shares closed up $1.35 to $86.36 on the New York Stock Exchange.

(Reporting by Bill Berkrot; editing by Carol Bishopric)