Chrissie Kenton, from First Artists Licensing, who is helping market the goods for Sega, said: "Ideally, the target is for male 16-25 year olds, but we're also looking at the men in their early thirties.
"A lot of men go away from computer games in their late twenties while they marry and have kids, and then in their thirties computer games become a sort of hobby for them."
Sega's main market will be men who still play their sports games and want to look "cool and trendy."
Ms Kenton said: "It's a first, and branding is very much the way forward. It could lead to loads of other items being sold, including chocolate."
One of Sega's main computer games rivals, Sony, says it is already selling T-shirts, tops and sportswear on a smaller scale through its Sony PlayStation magazine.
A spokeswoman said: "It's relatively new, and only available in the UK. But sales are going well, and if it takes off we might consider selling via the Internet."
Major retailers C & A, Debenhams and the House of Fraser are all planning to stock Sega clothes, which could be available as early as this summer.Reuse content