Shares in Dutch deep-sea prospector Fugro fell 4.5 percent on Monday after larger rival Boskalis announced that it had trimmed its holding in the company.
A statement from dredging and marine engineering company Boskalis said that its holding in Fugro now stands at 24.9 percent. Boskalis had built a stake of as much as 28.6 percent at the end of 2015 in what was widely seen as a first step towards buying Fugro.
Boskalis also took Fugro to court in an attempt to strip away some of the company's poison pill defenses but lost its case in May.
Fugro shares were down 4.5 percent at 14.74 euros by 1641 GMT. They had been trading around 15.14 euros shortly before the news was announced.
Boskalis spokesman Martijn Schuttevaer said that Boskalis would not comment on "any consideration, motivation or underlying strategy" behind the move.
Dutch market rules require investors to report to market regulator AFM when they cross above or below an ownership threshold of 25 percent of a listed company. (Reporting By Thomas Escritt and Toby Sterling; Editing by David Goodman)