Complex sentence: He started service on September 19,1977 in the Trade and Industry Ministry as the Assistant Director (Domestic Trade) until 1982, and as Principal Assistant Director (Trade Development) until 1988.
Split into simpler sentences: He started service on September 19,1977 in the Trade and Industry Ministry as the Assistant Director (Domestic Trade), a position that he held until 1982. He then held the title of Principal Assistant Director (Trade Development) until 1988.