A nationwide alert has been issued for an assistant manager at the W. Bell & Co. store in Silver Spring who was missing after the theft of cash, jewelry and camera equipment from the store, Montgomery County police said.

Paul A. Dubose, who worked at the New Hampshire Avenue store, was last seen by several employes about 8:30 p.m. Friday, when the aisles were teeming with holiday shoppers, police Sgt. Harry Geehreng said. He said the missing items are worth as much as $200,000.

Montgomery County police and Bell officials said they believe that Dubose may have been a victim of foul play. "We have no reason to think anything else," said Senior Vice President Fred Bell, who valued the missing cash and merchandise at $50,000.

Geehreng said that Dubose's disappearance was discovered about 7:30 a.m. yesterday when another manager, in charge of opening the store, noticed that several gold rings and bracelets had been taken from a display case. He tried to call Dubose, one of three managers on duty Friday night, and found that he had not been home.

Montgomery County police discovered later that Dubose apparently had entered the office and the safe area about 1 a.m. yesterday, one hour after the store's midnight closing, according to records provided by the store's alarm company. Dubose had to call the company and identify himself in order to get in, police said. Dubose's car, a 1968 light-blue Chevy Nova with Maryland license plates, is also missing.

Dubose was described by police as 5-feet-11, 220 pounds, with brown hair, green eyes and a full beard.

Bell said Dubose joined the company three years ago in a junior position and had advanced to assistant manager. He said Dubose lives in suburban Maryland.

In a telephone interview yesterday, a woman who identified herself as Dubose's wife sobbed as she said she is worried about her husband. She declined to say when she had last seen him.