First Bank System discovers merging funds is hard to do. (Brief Article)

When Midwest giant First Bank System Inc. gobbled up the much smaller Boulevard Bancorp in May, it not only fattened its banking empire, it added heft to its mutual funds.

First Bank did this by merging Boulevard's funds into its own proprietary mutual fund family.

A handful of banks have had similar experiences, and more are likely to, as banks continue to get into the mutual fund business and as bank mergers continue apace.

But First Bank's experience is educational on one point. While the merger was successful, a senior official said the company was surprised by how hard it was to handle the combination.

"It has not been an easy …