Simplify the following text for a Grade 10 native English-speaking person.
Original: Eni operates in engineering , oilfield services and construction both offshore and onshore through Saipem , a subsidiary listed on the Italian Stock Exchange ( Eni 's interest is 43 % ) .
Simplified: Eni operates Saipem , a subsidiary , and owns 43 % of the company . Saipem works in engineering , and oilfield services and construction .