SEOUL - Samsung Heavy Industries Co Ltd and Samsung Engineering Co Ltd, affiliates of South Korean conglomerate Samsung Group, said on Thursday they have no plans to merge with each other. Samsung Heavy and Samsung Engineering shares rose sharply on Wednesday after Samsung Heavy Chief Executive Park Dae-young said the two firms should eventually merge for long-term synergy. But the two firms said in separate exchange filings on Thursday that no such a deal was being considered. Samsung Heavy’s 2014 takeover attempt of Samsung Engineering failed due to shareholder opposition.