The phrase "additional companies" is correct and usable in written English.
It can be used when referring to more companies beyond those already mentioned or considered.
Example: "In addition to our current partners, we are looking to collaborate with additional companies in the tech sector."
Alternatives: "further companies" or "more companies".
The new infrastructure brought to serve AOL is now attracting additional companies.
The company says it has conducted transactions for 45 companies and is qualifying 200 additional companies.
After some companies provided internal ethics data, 15 additional companies, including Lockheed Martin, Boeing and Raytheon, were given A's.
These firms often subcontract additional companies to do the hiring, manage the payroll and handle other functions.
In the 19th century, it was standard practice for a new opera to be revised, sometimes extensively, after its premiere, as additional companies produced it.
And an American reporter traveling with American and Iraqi troops saw that several additional companies had been sent into Sadr City on Saturday.
Within five years, he said, he plans to franchise 30 stores plus open four additional company-owned locations.
Among them, she said, were letters from shareholders who said that this additional company-specific information will be important to them when they are considering CEO compensation.
During its service in Iraq, the 205th Brigade was unusually large, made up of eight battalions and an additional company, more than double its normal three-battalion complement.
In connecting runners with those unable to leave their flat, those recently widowed, or those that simply crave a bit of additional company, Goodgym creates reciprocally beneficial relationships amongst members of the community.
Office Live also offers storage space on the Web; additional company-branded e-mail accounts and calendars; and the ability to chat online via text, voice or mobile phone with employees, customers and colleagues with Windows Live Messenger.
