HARTFORD — George L. ‘‘Doc’’ Gunther, a fixture in the Connecticut Senate, died Sunday after a long battle with cancer. He was 92 and had served in the state Senate for four decades.

In a statement Sunday, Governor Dannel P. Malloy credited Mr. Gunther for fighting to protect the environment and preserve open space

Mr. Gunther, a Republican, represented the towns of Shelton, Stratford and parts of Monroe and Seymour from 1966 until he retired in 2006.

The newspaper says he was the longest-serving senator in state history.

In interviews with the Connecticut Post, Mr. Gunther took credit for helping pass key conservation laws such as the tidal wetlands law in 1969 and legislation to recycle bottles following an eight-year battle.