COPENHAGEN — Denmark gave approval for Gazprom’s Nord Stream to place its natural gas pipeline through its territorial waters in the Baltic Sea on Tuesday, making it the first country to grant final permission for the project.

Denmark approved the 137-kilometer Danish stretch of the pipeline that will connect Russia with Germany, the Danish Energy Agency said. The 1,220-kilometer link will also pass through Finnish and Swedish waters and requires permission from all five nations.

“We have investigated the safety and the environmental aspects of the project very thoroughly,” Kirsten Lundt Erichsen, an engineer with the Danish agency, said by telephone.

Nord Stream can start construction in four weeks, she said.

The Nord Stream venture, which includes BASF’s Wintershall Holding and E.ON Ruhrgas, seeks to transport 55 billion cubic meters of gas a year when it’s completed in 2012. The project has been delayed by a year because of adjustments to routes and environmental reviews.

Finland approved the environmental aspects of Nord Stream’s application in July, paving the way for the government to give final approval. Russia is completing its approval, said Frank Dudley, a Nord Stream spokesman.

“We’re confident to receive permits from all the other countries by the year-end,” he said. “Every administration works differently.”

The pipeline will cross Danish territory around the country’s Baltic Sea island of Bornholm, some 160 kilometers east of Copenhagen.

Prime Minister Vladimir Putin discussed Nord Stream “in detail” with Danish counterpart Lars Loekke Rasmussen on Sept. 16, according to the Russian government’s web site. Putin is scheduled to meet Finnish Prime Minister Matti Vanhanen on Oct. 25 in St. Petersburg during a business forum.