Muntean, who was Transgaz CEO between 2005 and 2007, replaces Ioan Rusu, the company said in a statement.
"As the new CEO is familiar with Transgaz operations we view the news as neutral," Raiffeisen Research said in a note to investors.
Majority state-owned Transgaz sees this year’s net profit rising to 313.9 million lei ($108 million/74 million euro) from 239 million lei last year.
Transgaz stock (www.transgaz.ro) is a component of the blue-chip index of the Bucharest bourse. The company shares traded 1.70% up at 155.6 lei by 0739 GMT on Tuesday.
(1 euro = 4.263 Romanian lei)