The former England striker, who terminated his contract at Turkish club Trabzonspor earlier on Monday, was first banned for two weeks in July 2019.
Sturridge was initially found guilty of two charges of instructing his brother to lay bets on a proposed move to Sevilla, but an appeal lodged by the Football Association proved a further two charges.
'He should make it for the City game' - Pochettino optimistic about Messi's injury
The 30-year-old’s ban was increased, ruling him out until June 17, while his fine was doubled to £150,000.
"Following an appeal by the FA of the previous findings of the independent regulatory commission in this case, an independent appeal board has found that the regulatory commission misapplied the FA's rules in relation to the use of inside information and made findings of fact which could not be sustained," read a statement from the FA.
"As a result, the appeal board has found proven two further charges which were originally dismissed. Other factual findings of the regulatory commission were left undisturbed.
"In relation to the sanction, the appeal board agreed with the FA that the penalty originally imposed on Mr Sturridge was unduly lenient and therefore increased his effective playing ban from two weeks to four months. The appeal board also doubled the fine to £150,000."
Chong swapping United for a European powerhouse - Euro Papers
'City played really good in CL final' - Guardiola ahead of trip to Chelsea
‘Fun and offensive’ Mourinho to clash with ‘master tactician’ Sarri in Rome - Inside Europe