Sri Lanka Freedom Party's Majeed was sworn in by President Mahinda Rajapaksa, presidential spokesman Wijayananda Herath said.
The leader of the main Muslim party - Sri Lanka Muslim Congress (SLMC) - Rauff Hakeem was present at the swearing in ceremony, Herath said.
There was uncertainty over the formation of the governing council of the province since the election was held on September 8. No party was able to command absolute majority in the 37-member council.
The ruling United People's Freedom Alliance (UPFA) and allies finished with 15 seats. The main Tamil party TNA won 11 seats while the SLMC 7 seats. The main opposition UNP secured 4 seats.
The SLMC, which fought the election independent of the ruling coalition despite its leader Hakeem was a central minister, was under pressure to support the opposition parties to form the council.
The TNA had publicly invited the SLMC to join them to run the province claiming that the mandate the SLMC had received at the polls was to work against the government.
The Eastern Province which is multi-ethnic consists of almost equal number of population representing Sinhalese, Tamils and Muslims.
