Complex sentence: An unwise investment in the unsuccessful Twin Buttes mine in southern Arizona further weakened the company, and in 1977 Anaconda was sold to Atlantic Richfield Company (ARCO) for $700 million.
Split into simpler sentences: An unwise investment in the unsuccessful Twin Buttes mine in southern Arizona further weakened the company. In 1977 Anaconda was sold to Atlantic Richfield Company (ARCO) for $700 million.