Sources close to Zefer say the Boston-based e-business integration house has filed for Chapter 7 bankruptcy and let go the rest of its employees.

Calls to Zefer's headquarters here were answered by a temporary receptionist with no knowledge of the company's situation.

A spokeswoman for NEC would neither confirm nor deny rumors that NEC had acquired assets from the company ranging from employees to clients to computer hardware.

A former Zefer employee, who quit the company earlier this year, said that about 180 Zefer people were offered jobs with NEC. Other employees were let go with neither severance pay nor expense reimbursement, the former employee said.

In March, NEC and GTCR Golder Rauner contributed $48 million to Zefer, but it evidently wasn't enough to save the once-high-flying e-services consulting firm, which in better times served clients like Heinz and Citibank.

Calls to GTCR Golder Rauner, which has funneled millions more into Zefer since 1999, were not returned.

Zefer sustained multiple rounds of layoffs in 2001, culminating with last month's departure of CEO Bill Seibel. Sources say Seibel was asked to step down.

According to GTCR's investment profile, Zefer employed 470 people in five offices at its peak.