AMSTERDAM (Reuters) - Dutch builder Royal BAM Groep (BAMN.AS: Quote, Profile, Research) expects a lower profit this year and to sell its minority stake in a dredging company, it said on Thursday after reporting strong 2007 results, partly due to a one-off gain.

The Netherlands' largest construction group said a net profit of at least 250 million euros ($393 million) was "feasible" in 2008, with sales seen at 9 billion euros.

BAM more than doubled net profit to 349 million euros in 2007 from 137 million euros a year ago, helped by the sale of U.S. unit Flatiron. Excluding the one-off gain, net profit rose to 277 million euros on sales up 3.6 percent at 8.95 billion euros.

Rabo Securities analyst Michael Roeg said BAM's outlook for 2008 was a relief.

"2008 should face a tough base due to absence of Flatiron profits, a slightly weaker pound, and some smaller special items that will probably not recur in 2008," he wrote in a note.

BAM shares were up 2 percent at 13.60 euros by 0814 GMT, outperforming a 0.8 percent drop in the mid-cap index .

BAM said it would start talks soon on selling its 21.5 percent stake in dredging company Van Oord. The Van Oord family and NPM Capital own 51 percent and 27.5 percent, respectively, of the dredging firm.

The stake is worth about 500 million euros, said Roeg.

"The investigation is expected to lead to conclusions in the course of 2008," BAM said in a statement.