LAGOS, Nigeria (AP) — Nigeria’s communications agency says a letter setting out reductions in a massive fine for MTN had a typo — one worth half a billion dollars.

Spokesman Tony Ojobo of the Nigerian Communications Commission told the AP Friday that the “initial letter” informed MTN its $5.2 billion fine is being reduced by 35 percent, instead of 25 percent.

MTN announced Thursday that its fine had been reduced to 674 billion naira ($3.4 billion). Ojobo said the actual amount is 780 billion naira ($3.9 billion).

The commission fined the South Africa-based telecoms company for failing to deactivate 5.2 million unregistered cellphone SIM cards by an August deadline.

MTN Group spokesman Chris Maroleng said he could not comment as negotiations continue.