While it plans to lease an initial four 170s from Finnair - the first having arrived at Tallinn last week, bearing a new livery - the carrier has agreed to purchase three 175s and a 190, said Embraer, for delivery in 2014.
Embraer indicated that Finnair would also take another four 190s under third-party or lease agreements.
The carrier had said it would use the aircraft to replace Boeing 737s.
But Estonian Air president Tero Taskila has also confirmed that the Embraers will also replace the airline's CRJs. Estonian had been in line to receive CRJ900s through a broad fleet modernisation deal brokered by SAS Group, which previously owned 49% of the carrier.
The first of these CRJ900s only arrived in early 2011, by which time SAS Group had opted to divest most of its stake in Estonian Air. Estonian Air operates three of the type. Last November it highlighted the CRJ900's operating economics and speed as it disclosed that it was negotiating for additional regional jets.
Taskila did not give a reason for defecting from the CRJ, but said a single-family operation would offer capacity flexibility to "pursue our immediate expansion and fleet modernisation objectives".
"The aircraft will deliver a standard of in-flight experience that will keep us competitive and allow us to access new markets with lower risk than using larger jets," he added. Estonian Air also indicated interest in Embraer's proposed re-engined E-Jet family.