By Lais Martins
SAO PAULO (Reuters) - Brazilian centre-left presidential candidate Ciro Gomes said on Tuesday that he would undo a $4.75 billion joint venture planned by Boeing Co <BA.N> and Brazilian planemaker Embraer SA <EMBR3.SA> if he wins this year's election.
Boeing plans to acquire 80 percent of Embraer's commercial aircraft arm, which together with the recent Airbus-Bombardier tie-up represents the biggest realignment in the global aerospace industry in decades.
Speaking at a business event in Sao Paulo, Gomes called the proposed deal "hostile" to Brazil's interests and a threat to the country's national security.
Gomes said he has written to the companies suggesting they end their partnership announced earlier this month.
Boeing and Embraer did not immediately reply to requests for comment.
Boeing and Embraer are expected to take until next year to hammer out all the details of a deal that will thrust the world's largest planemaker into the regional jet market. That means final approval of the joint venture will be up to Brazil's next president, who will be elected in October.
Gomes is running third in early polling with 8 percent of voter support, behind environmentalist Marina Silva with 13 percent and far-right politician Jair Bolsonaro, who is the front-runner with 17 percent.
Government opposition to a wholesale take-over of Embraer by Boeing led to the plan for a joint venture involving the Brazilian company's regional jet arm, but excluding its defence and business jet divisions.
(Reporting by Lais Martins; Writing by Anthony Boadle; Editing by Leslie Adler)