SAIPAN, Northern Mariana Islands (AP) _ Larry Hillblom, the multimillionaire co-founder of DHL Worldwide Express, was killed in a plane crash north of this western Pacific island. He was 52.

Hillblom and two other men left Saipan on Sunday for Pagan Island, 290 miles north of here. They were going to explore mining ash from a volcano but the weather forced them to turn back, said David Ecret, a spokesman for the governor.

The pilot, Robert Long, apparently sank with Hillblom's twin-engine amphibious plane after it went down Sunday night 45 miles north of Saipan, Ecret said. His body wasn't immediately found and a search continued early Tuesday.

Also killed was Jesus P. Mafnas, vice speaker of the House of Representatives of the Commonwealth of the Northern Mariana Islands, of which Saipan is a part.

The bodies of Hillblom and Mafnas were found.

It is possible the plane ran out of fuel since the three had planned to refuel on Pagan Island and never made it, Ecret said.

Although the plane was equipped to land on lakes and rivers it was not designed to land on the open ocean, Ecret said.

Hillblom, 52, a resident of Saipan for about 10 years, had numerous business interests here, including cable television and airlines. He was a practicing attorney and occasionally served as a special judge for the commonwealth.

Hillblom founded DHL with Adrian Dalsey and Robert Lynn in 1969; the company's name comes from their initials. Dalsey died last year and Lynn left the company shortly after its founding, said DHL spokesman Dean Christon from company headquarters in Redwood City, Calif.

Hillblom remained a major shareholder in the $3 billion-a-year air courier company but was not involved in its operations, Christon said.

In August 1993, Hillblom was seriously injured and lost the sight in one eye in a plane crash while attempting to land at Tinian, the commonwealth's capital.

Saipan is the main island in the Commonwealth of the Northern Mariana Islands, about 4,000 miles west of Honolulu.