The income from taxes on operators' profits will be a useful source of income for Spain as it struggles to rein in its deficit.
Spain's Treasury said it was informing companies of the outcome of their license applications on Friday but would not release a list of those who had been successful until next week when sites can go live.
Spain is one of Sportingbet's main markets and the company's operations there have been suspended since March because of a legal injunction won by Spanish casino group Codere.
"The grant of the eGaming license negates part of the injunction, which was imposed on Sportingbet's Spanish business on 27 March 2012 and thus allows Sportingbet's Spanish business at www.miapuesta.es to commence trading when this regulated market opens," Sportingbet said. The company is applying to a court in Madrid to have the rest of the injunction lifted.