SOFIA (Reuters) - Bulgaria's president will name diplomat Marin Raikov as interim prime minister, two sources with direct knowledge of the process said on Tuesday, as he seeks to shore up confidence after protests felled the previous administration.

"Marin Raikov is going to be the new prime minister," said one source, who declined to be named as the information was not public yet. The interim government will serve until an early election scheduled for May 12.

The presidency, which is due to announce the interim administration at 4 p.m. (10.00 a.m. ET), declined to comment.

(Reporting by Tsvetelia Tsolova; Editing by Sam Cage and Editing by Kevin Liffey)