Air Peace has increased the number of Embraer 195-E2s it has on firm order, from 10 to 13, by converting purchase rights acquired under the earlier deal.
The Nigerian carrier took 20 purchase rights when it firmly ordered 10 E195-E2s in April.
Embraer notes that Air Peace will receive the first of the aircraft in the second quarter of 2020 and become the first E2 operator in Africa, as well as the launch customer for the Brazilian manufacturer's new "premium staggered seating" option.
Passengers will "experience an unparalleled level of comfort, especially in first class", vows Embraer's vice-president of sales for Africa and Middle East, Raul Villaron.
Air Peace chief executive Allen Onyema describes the order as "a further confirmation of our 'no city left behind' initiative".
He says the airline has been "receiving impressive data about the aircraft's economics now that it is in revenue service". The E195-E2s will be used to "enhance connectivity in Nigeria and the African region, while feeding long-haul flights from our Lagos hub", he adds.
The airline's Air Peace Hopper subsidiary last year started operating six ERJ-145s on "short thin routes", notes Embraer.
Cirium fleets data shows that Air Peace has 12 737s in service and 10 Max jets on order. It also operates a trio of 777s and a Dornier 328Jet.