Fewer than eight months after HFS Inc. bought PHH Mortgage Services,  the mortgage company is aggressively expanding its staff. 
PHH has been adding 80 to 100 employees per month, bringing its payroll  close to 1,900. In October it said its staff eventually will swell to   3,100. And construction of a new headquarters is to begin in the next two   to three months.     
  
"We're adding now to meet the business volume that we have," said  Kenneth E. Harthausen, senior vice president for sales and account   management for the Mount Laurel, N.J., company.   
For competitors, PHH's buildup-underscored when New Jersey Gov.  Christine Whitman made a campaign stop when the company announced its new   headquarters - might have an ominous feel about it.   
  
PHH's merger with HFS of Parsippany, N.J., in April promises to extend  PHH's reach through a huge network of real estate brokers and other   affiliates.   
Through Century 21, Coldwell Banker, and ERA, HFS has a network of  nearly 12,500 offices with more than 180,000 brokers in the United States   and overseas.   
"Even if PHH is only modestly successful in penetrating these three real  estate brokerage companies," said Stuart A. Feldstein, president of SMR   Research Corp., Hackettstown, N.J., "PHH could still become a huge mortgage   originator merely because the three brokerage companies are so large."     
  
In addition, the family of HFS companies also includes the third-largest  corporate relocation service in the world, HFS Mobility Services. 
A result of the merger of Coldwell Banker's relocation service and PHH  Corp.'s relocation unit, HFS Mobility has a 52% market share, Mr.   Harthausen said. About 1.2% of all mortgages in the United States come   through PHH Mortgage Services, but "we have just scratched the surface of   taking advantage of HFS' advantages," he said.       
Nationally, 80% of mortgage operations affiliated with real estate  brokerages have been profitable this year, said Weston E. Edwards,   president of Weston Edwards and Associates in Laguna Beach, Calif. Most are   earning more on each mortgage than on the related home sale, he added.     
This contrasts with 1995, when 58% of mortgage operations tied to real  estate agents were losing money, Mr. Edwards said. 
  
Real estate agencies owned by or affiliated with HFS are not required to  use PHH Mortgage Services, Mr. Harthausen said, but PHH has an edge. 
HFS and PHH are working to change the outlook of homebuyers. "They're  trying to see if they can cause the customer to look to the firm as opposed   to the sales agent as the source of their benefit," Mr. Edwards said.   "They're trying to do it by putting together a package of attractive   services."       
PHH originated nearly $4.3 billion of residential mortgages in the first  half of 1997, according to a ranking of the top 100 originators of   residential mortgages published by American Banker.   
Mr. Harthausen said PHH was recently ranked in the publication Inside  Mortgage Finance as the 10th-largest originator of loans and that it had   originated slightly more than $7.8 billion through September. PHH   administers a $28 billion portfolio of mortgage loans.     
Another merger that is expected to close by yearend-HFS' merger with CUC  International Inc., to form Cendant Corp.-could also create opportunities   to expand the mortgage business. But analysts said the engine for mortgage   growth was put in place by the earlier deal.     
"I think it's gone exceptionally well," said Mark R. Miller, equity  research analyst at Merrill Lynch & Co. "The mortgage business is one of   the fastest-growing parts of the business right now.   
"All of HFS has huge cross-selling opportunities, and those show up in  all the businesses. And PHH is one that probably sees some of the strongest   cross-selling opportunities, Mr. Miller said. "Their growth has been   phenomenal and will continue for the foreseeable future."     
Walter C. Klein Jr., president and CEO of First Nationwide Mortgage  Corp., said, "It's not easy to do, but it's one of the more strategic   relationships, to affiliate the home seller and a major mortgage provider.   
"We worked years at it to make it successful, and I always thought it  was worth the effort," said Mr. Klein, who as chief executive of Sears   Mortgage Corp. fostered a relationship with Coldwell Banker. "That   strategic alliance is one of the great competitive advantages for the 21st   century."