As per the terms of the deal, Aker will also have an option to buy the remaining 30% of CSE three years after the completion of the transaction.
Financial terms of the deal were not disclosed.
CSE is engaged in providing maintenance, assembly, commissioning and crane operation services at offshore and onshore facilities.
Schedule to be completed by the end of the first quarter of next year, the deal is subject to approval by Brazilian competition authorities.
Aker said that the acquisition will provide access to Brazil's growing market for servicing existing oil and gas fields.
Aker Solutions CEO Luis Araujo said: "Aker Solutions has established a solid presence and reputation in Brazil's oil and gas market over the past 40 years and entry into the country's brownfield segment is an attractive growth opportunity.
"Joining forces with a successful local player like CSE fits well with the internationalization of our services business, allowing us to bring our competence, knowledge and experience within this field to this important and growing region."
Following the acquisition, CSE will remain a separate legal entity with a management team comprising personnel from each company.
CSE CEO Altair Dietrich said that the combined company will expand capabilities and create significant value for customers.
Dietrich added: "Teaming up with Aker Solutions is a huge step for the company and puts us in the next league in terms of competing for even larger and more complex contracts."
CSE has a fabrication facility in Rio das Ostras is located near Aker Solutions' subsea services facility.
