A tired, sunburned man with thinning blond hair and mud- soaked clothes stepped calmly before a crowd of reporters here Tuesday and provided a minimum of information.

"My name is Gene Hasenfus, " he said after a Sandinista army officer whispered in his ear. "I come from Marinette, Wisconsin. Yes, and I was captured yesterday in southern Nicaragua. Thank you."

Wearing jeans, a blue T-shirt and a light blue work shirt -- all covered with grime after he parachuted into Nicaragua's rain-drenched jungle -- Hasenfus then turned and was led off without another word.

Asked why reporters were not allowed to speak to the fatigued but fit-looking survivor at the evening news conference, Sandinista Army intelligence chief Capt. Ricardo Wheelock said, "He is in shock. How are we going let him speak to you?"

However, Wheelock said that as soon as the Sandinistas were done interrogating Hasenfus, probably within two days, reporters would be allowed to interview him.

Earlier, Hasenfus was allowed to speak to local journalists briefly in San Carlos, a port on Lake Nicaragua near the crash site. He said only that the plane began its journey in Miami, picked him up in El Salvador, then took a Nicaraguan aboard in Honduras and entered Nicaraguan airspace from Costa Rica at a site known as La Noca on the San Juan River.

It was up to Sandinista army officers to fill in some of the huge gaps in Hasenfus' story. As Lt. Col. Roberto Calderon unraveled the tale, it pointed to Americans flying supply missions for anti-Sandinista contra rebels with the assistance of El Salvador's armed forces.

U.S. DENIAL

U.S. and contra officials have said in interviews this year that supply flights to rebel troops, mostly those of the Nicaraguan Democratic Force, have been made by contra pilots and Americans working on contract for the rebels. Calderon did not specify which contra factions the downed plane was to have supplied.

U.S. officials Tuesday denied any connection to the flight. Calderon, military chief for Nicaragua's Fifth Military Region, said Hasenfus parachuted to safety as the plane in which he was flying on a supply mission for the rebels was shot down at 12:45 p.m. Sunday, killing two other Americans identified as Wallace Blaine Sawyer and William J. Cooper, and an unidentified man "of Latin origin."

In the first few hours after his capture at about noon Monday, Calderon said, Hasenfus told Sandinista military officials that the flight was his fourth since July out of Ilopango Air Base outside San Salvador, the Salvadoran air force's headquarters.

Backing up the explanation, the Sandinista commander produced laminated identification cards bearing the Salvadoran air force insignia, issued in July of this year to Hasenfus and Sawyer, whose photo showed a blond, middle-aged man. Calderon said Sawyer was co-pilot of the ill-fated flight.

The cards, which closely resembled other identification issued by the Salvadoran military, were marked "restricted area, " "Spec.: (specialty) Adviser" and "Group: USA."

CONTRACT MISSION

On the basis of the ID cards, Sandinista officials originally identified Hasenfus as a U.S. military adviser assigned to the Salvadoran armed forces.

But other information and identification taken from Hasenfus and the charred bodies of the two other Americans suggested a contract mission by veteran American free-lancers.

Cooper, who Calderon said had piloted the downed C-123 transport plane, appeared in a white shirt and tie on a card identifying him as a captain for Southern Air Transport, a Miami-based cargo carrier.