Complex sentence: In the 1980s the company was still the market leader in France and North Africa, it acquired "Grands Travaux de l’Est" which was the starting point for expansion into the countries of the Indian Ocean, and of its civil engineering activities.
Split into simpler sentences: In the 1980s the company was still the market leader in France and North Africa. It acquired Grands Travaux de l’Est, which was the starting point for expansion into the countries of the Indian Ocean and of its civil engineering activities.