There have been examples of cooperation, too. Citicorp, which also markets credit cards in Canada, entered into a joint investment services venture with Bank of Montreal, as did Mellon Bank Corp. with Canadian Imperial. Royal Bank is a shareholder in two U.S.-based electronic banking ventures, Integrion Financial Network and Meca Software. Northern Trust Corp. of Chicago, which provides asset management services to Canadian companies, is seen as another potential merger partner in Canada. So are the Minneapolis companies U.S. Bancorp and Norwest Corp., in part because of their proximity to the border and business overtures they have already made. Bulked-up U.S. and/or Canadian banks may be increasingly attractive to a buyer from elsewhere, such as HSBC Holdings of London, which owns a sizable Canadian banking operation as well as Marine Midland Banks in Buffalo.