Complex sentence: In September 1961 another pirate radio station began to compete under the name DCR/The Commercial Radio of Denmark (Danmarks Commercielle Radio), that was started by a group of former Mercur employees.
Split into simpler sentences: In September 1961 another pirate radio station began to compete under the name DCR/The Commercial Radio of Denmark (Danmarks Commercielle Radio). This was started by a group of former Mercur employees.