HARRISBURG, Pa. (7/7/09)--A Pennsylvania-based credit union has filed suit against a local bank alleging that the bank's symbol, a big red "M," infringes on the credit union's trademark. Members lst FCU, a $1.545 billion asset credit union in Mechanicsburg, filed the suit June 19 in U.S. District Court in Harrisburg, alleging that Metro Bank, which is based in Harrisburg, is using a big red M as its symbol. The complaint said that on or about March 1, 2003, the credit union began using its current red M logo. Since then, it has spent millions of dollars in advertising and marketing to promote its M logo (Pennlive.com July 6). The bank unveiled its logo in June as part of a conversion of Commerce Bank/Harrisburg to Metro Bank, said the article. Metro's M has a break in the left side of the M, while Members 1st M has a break on the right side to form part of the letter M as "1st." The two logos are so similar that both bank customers and credit union members have walked into the other institution's branches, thinking they were their own institutions, the credit union told the publication. The complaint alleges that the bank adopted the logo "in an effort to capitalize on Members lst's goodwill and thereby obtain a competitive advantage" in the midstate market. The bank said it would not comment about ongoing litigation.