The president on Monday night signed a proclamation extending the tough laws by a further month, an official who declined to be named said.
The move also leads to the automatic re-instatement of the parliament which was dissolved last month to clear the way for elections just two months ahead of schedule.
"The parliament now stands re-convened until the elections are conducted on April 8 and the new assembly holds its first sittings on April 22," the official said.
The president can extend the emergency for a period of one month at a time, but it must be ratified by parliament within 10 days.
Sri Lanka has faced criticism over the use of emergency laws, which were imposed in 1983 to combat Tamil Tiger separatists who waged a 37-year battle against the state until last May, when they were wiped out by the army.
The government argues that although Tamil guerrillas have been defeated, rebel remnants were trying to make a comeback, a claim rejected by Sri Lanka's opposition w