Fluor Corp, the largest publicly traded U.S. engineering company, reported a better-than-expected profit along with growth in its order backlog despite a very challenging economic environment.

Fluor said on Monday that its second-quarter net income fell to $169 million, or 93 cents per share from $208 million, or $1.12 a share in the year ago period, which included 27 cents made on the sale of a stake in a wind farm.

Analysts, on average had expected 91 cents, according to Reuters Estimates.

Also on Monday, smaller rival McDermott International Inc reported a decline in second quarter net income to $92.6 million, or 40 cents per share, from a record $177.5 million, or 77 cents per share, in the same quarter a year before. Analysts had expected a second-quarter profit of 37 cents per share.

Fluor's backlog on June 30 had grown to $30.9 billion from $29.1 billion three months before, helped by its win of a contract to build the first phase of Imperial Oil Ltd's Kearl oil sands project in Alberta.

Chief Executive Alan Boeckmann reiterated his view in a conference call with analysts that the backlog would be over or within shouting distance of $30 billion by year-end, though he did see a tremendous amount of unease among clients about the strength of oil and gas prices.

Fluor's oil and gas segment backlog, for example, has dropped by 25 percent since last year to $15.8 billion.

While we have posted strong results to date, we remain sensitive to the pace of global economic recovery which could impact the timing of future new awards, Boeckmann said in a statement.

Fluor stuck with its full-year profit outlook of $3.80 to $4.10 per share.

Shares of Fluor slipped 24 cents in after-hours trading to $57.25 after closing 1.2 percent lower on Monday.

The stock has risen by 28 percent so far in 2009, compared with a 12 percent rise for the S&P 500 index .SPX.

Rivals Jacobs Engineering Group Inc and Quanta Services Inc, which are similarly reliant on the energy industry for business, also sounded cautious notes along with their quarterly results. [ID:nBNG469190] [ID:nBNG541198]

URS Corp (URS.N) is due to report results on Wednesday.

 (Reporting by Braden Reddall; editing by Andre Grenon and Carol Bishopric)