Marriott Corp. President J.W. Marriott Jr. was reported in stable condition and "resting comfortably" in a Boston hospital yesterday following an explosion Saturday at his summer home in New Hampshire.

Marriott, 53, who is also chief executive officer of the Washington-based hotel and restaurant conglomerate, received first- and second-degree burns in the blast, which occurred at a boathouse at the Marriott family compound in Mirror Lake, N.H. He is expected to be released from Massachusetts General Hospital "in a few days," corporate spokesman Al Rankin said yesterday.

No other injuries were reported in the accident.

The explosion occurred 11 days after Marriott's father, J. Willard Marriott Sr., founder of the Marriott Corp., died of a heart attack while vacationing at the Mirror Lake compound.

A local fire official said Marriott was fueling a boat in his one-story boathouse at Tuftonboro Neck about 9:40 a.m. Saturday "when somehow a spark ignited and away it went." The force of the blast "blew him out into the lake," the official said.

Marriott was taken to Huggins Hospital in Wolfeboro, N.H., by private car and then transferred to Massachusetts General by helicopter.

Marriott was appointed president of Marriott Corp. in 1964 and chief executive officer in 1972. In addition to a worldwide chain of 144 hotels, the conglomerate includes 2,500 fast food restaurants, airline flight kitchens and catering services.