In 1968 Lauritz Knudsen A/S merged with another major switchgear manufacturer, NES. Through the next decade the company was named LK-NES. The early product range of generator control and alarm systems was marketed under the name NESELCO.

In 1984 SELCO A/S was established as a joint venture between Lauritz Knudsen A/S, Technical Manager Hans Jakobsen and Sales Manager Jens Hammer Sørensen. 1997 Managing Director Jens Hammer Sørensen became the only shareholder of SELCO A/S.

To obtain the right environment for further growth, SELCO moved in 2005 to new and larger premises in Roskilde, Denmark.
This became head office for administration, development, test, quality assurance and Marketing. Allready then SELCO had subsidiaries and many local partners reaching customer relations in more than 60 countries all over the world.

As part of a generational change SELCO A/S was on 3rd August 2011 acquired by the American organisation Littelfuse Inc.

Now Littelfuse Selco operates as part of this organisation.