BOSTON – Kessler Financial Services, long considered a brokerage firm with ties to credit card giant MBNA, should more properly be understood as MBNA's business development arm when it is working with credit unions, according to Steven Fuld, Senior Vice President of the Boston-based company. "In the area of affinity marketing we really are the business development arm of MBNA," Fuld said, pointing out that the firm represents the Delaware-based credit card issuer in other affinity deals, such as those with alumni groups, labor unions and others. The firm will still broker credit card deals, even from credit unions, to other issuers if MBNA passes on them first, Fuld said, and still maintains relationships with other firms in other parts of its business. Critics of Kessler have long pointed out that a company calling itself a brokerage should be able to offer its clients access to more than one firm when marketing a credit card portfolio.