Suez, the French power company planning to merge with Gaz de France, said Tuesday that it more than doubled its stake in Spanish rival Gas Natural.
In total, Suez said it will own 11.3% of Gas Natural when it completes the transaction. The company previously held 5.4% of Gas Natural.
"Suez's investment in Gas Natural, Spain's gas market leader, is in line with the group strategy to expand dynamically in the European energy and environment markets," the company said in a statement.
Suez shares slipped 0.2% to 42.32 euros ($57.32) in Paris.
The company is determined to finalize its planned merger with French state-owned gas company Gaz de France, Suez Chairman Gerard Mestrallet said.
Plans to merge with GDF, announced more than a year ago by French Prime Minister Dominique de Villepin, have been left in limbo after a French court ruling postponed it until July 1, when energy markets fully open to competition.