UPDATE 1-Vallourec Q1 profit below expectations

(Adds CEO comment)

PARIS, May 7 (Reuters) - French steel tubes maker Vallourec (VLLP.PA: Quote, Profile, Research) reported lower-than-expected net profit for the first quarter on Wednesday but confirmed its estimate of a gross operating margin of 25 percent for the first half of the year.

Vallourec, the world's largest maker of seamless steel tubes, posted net profit of 193.3 million euros ($299.4 million), against a Reuters Estimates consensus forecast of 225.5 million euros.

Operating profit for the first three months fell to 310.7 million euros, down 21.5 percent, against a consensus estimate of 357 million euros.

Sales for the quarter totalled 1.384 billion euros, below the consensus estimate of 1.542 billion euros.

Vallourec CEO Pierre Verluca said the company was experiencing "very good market conditions" in the United States and was in a good position to raise prices to pass on increases in raw materials costs.

He declined in a conference call to give a forecast for second-half margins, however.

Vallourec confirmed it expected 2008 revenues at least equal to the sales for 2007, comparing like with like.