PARAMARIBO, Suriname (AP) _ The National Assembly on Tuesday unanimously elected agronomist Ramsewak Shankar as president and former Prime Minister Henck Arron as vice president.

Arron, 55, had been elected twice as prime minister and was ousted in a 1980 coup lead by Suriname's military leader, Cmdr. Desi Bouterse, who remains in control of the armd forces.

Shankar, 50, is an agricultural engineer who has been active in development programs but not in politics, although he was a Cabinet minister from 1969-72.

The two men will be sworn in Jan. 25.

On Nov. 25, voters elected members to the 51-seat National Assembly in the first general election since the coup. Bouterse had promised to put Suriname back on the road to democracy.

According to a new constitution adopted in a September 30 referendum, the president will have broad powers and the vice president heads the Cabinet. The presidency previously was a mainly ceremonial post.

''It is the first time that a president and vice president have been elected and they have far-reaching authority invested in them,'' the National Assembly president, Jaggernatch Lachmon, said in a short speech.

''They have no easy task and great responsibility. The National Assembly that harbors the power of the people will check their performance.''

Bouterse was not present for the assembly balloting, but the military was represented by Cmdr. Ivan Graanoogst and Capt. Chas Mijnals.

The outgoing prime minister, Jules Wijdenbosch, and President Fred Ramdat Misier attended the session.

Suriname is a former Dutch colony on the northern shoulder of South America.