Albion have persuaded the versatile 22-year-old to move to the Amex Stadium despite interest from a number of Premier League and Championship clubs in recent months.
Brighton manager Gus Poyet has sealed a deal for the player after he impressed during a training spell with the Seagulls late last year.
But the Albion boss has indicated Maksimenko is a long-term prospect, and unlikely to feature in the coming weeks for the club.
Poyet said: "We have been aware of him for a while. He can bring more quality to our first-team in the future.
"He has quality on the ball. He'll train with the development squad to learn the way we play. Then it's up to him."































