Robert Bradshaw, 61, premier of the British associated state of St. Kitts-Nevis in the Caribbean, died Wednesday at Basseterre, St. Kitts. Sources said Mr. Bradshaw had suffered from cancer of the spine.

Mr. Bradshaw first gained prominence when he was fired as a sugar cane cutter by white plantation owners in 1940 for trying to form a labor union.

He had led every government since St. Kitts-Nevis gained home rule in June 1967. His support was based on the unemployed and sugar workers in the islands.

Some felt that his "austere, audacious, and autocratic" reputation, along with his penchant for spending British aid on personal defense forces, led to the island of Anguilla's breakaway from the associated state in 1967.

St. Kitts-Nevis consists of two islands of about 104 square miles with about 48,000 inhabitants in the Lee-Rico. Its chief exports are sugar, molasses, cotton, and salt.

Mr. Bradshaw had been ill for some time. He underwent surgery in Britain in January and had returned home in mid-March.

Acting Premier Paul Southwell ordered government offices and schools in the island group closed as a mark of respect and announced one-week of mourning before a state funeral May 31.