Bankers keep fielding questions about when they are going to get back into the M&A game, and many keep giving the same answer: no time soon.

The ceaseless pressure from investors is understandable. If done effectively, deals can transform buyers, juice earnings and create oft-touted synergies. But big banks have been reticent to engage in any kind of substantial dealmaking, citing fears about delays, new regulatory burdens and contingent liabilities.

Executives from U.S. Bancorp, SunTrust and other banks sang the same tune at the Barclays Global Financial Services Conference in New York this week, though U.S. Bancorp Chief Executive Richard Davis added a few new lines.

Davis said he is avoiding acquisitions because he wants the company unencumbered when the economy takes off.

"We're getting close to this inflection point when things start to take off, and I do not want to have this company back on its heels integrating unless it's really worth it," Davis said at the conference.

Kelly King, the CEO of the $188 billion-asset BB&T in Winston-Salem, N.C., countered the conventional wisdom this week, arguing that banks like his can make decent-sized acquisitions if they demonstrate to regulators that they have the systems to handle them.

But executives at several regional banks said at the Barclays conference that they are flatly uninterested in buying other banks, keeping an inward gaze and primarily willing to entertain only niche deals.

"We're going to make one big acquisition, and that's SunTrust," said William H. Rogers, the chief executive of the $183 billion-asset Atlanta bank. "That's where the greatest opportunity is and where we can build the most shareholder value. We might do a little bit on the investment banking business and a couple of other little things. My focus is going to be on SunTrust."

Rogers' caveat about investment banking is an important distinction. Although larger banks have shied away from buying banks, several have spent the last few years beefing up side businesses that provide steady forms of fee revenue.

For instance, the $90 billion-asset KeyCorp in Cleveland has acquired commercial servicing portfolios over the last few years and recently acquired Pacific Crest Security, a boutique investment bank.

"What you see is us thinking smartly about how we can add to products, to capabilities and broaden our platform, which we think makes us more distinctive, more competitive," KeyCorp CEO Beth Mooney said. "In the case of Pacific Crest, it will be additive over time to our fee-income business."

Mooney added that she is also on the hunt for acquisitions in commercial payments or other fast-changing business.

KeyCorp is looking "to do some product capabilities or enhancements where you could do them potentially through joint venture, through the acquisition of a small company, she said.

Even then, a company has to tread carefully, the $389 billion-asset U.S. Bancorp's Davis said.

The Minneapolis company recently completed its acquisition of nearly 100 branches from the Royal Bank of Scotland's U.S. operations, and it has been an aggressive acquirer of fee-based businesses.

More deals like those are possible, but Davis said he wants to make sure the company remains balanced.

"We're not going to buy a big trust company and ended up having a big trust company with a few payment company projects, and we don't want to be just a big branch network with a couple of other things," Davis said. "We want to be well diversified in the way we show you here."

Smaller regionals and larger community banks are making up the bulk of the M&A activity. By most accounts, M&A is heating up among those banks.

Banks have engaged in 186 mergers or acquisitions year-to-date as of Friday, with transaction sizes on average $5 million larger than 2013, which saw 229 deals completed, Keefe Bruyette & Woods data show.

Yet caution remains the watchword.

TCF Financial Corp's CEO William Cooper is open to making the right acquisition, at the right price, but he is not willing to expand his $18.8 billion-asset bank more than 10%, he said.

"That is too fast in the banking business. We'd be somewhere below there," Cooper said at the conference, adding that the bank's niche origination channels for auto loans and equipment financing have attracted bundles of suitors over the years, but today's M&A market is still tough.

"The biggest banks are not in a position to acquire others, and other banks have announced acquisitions but have gotten stuck in limbo for years," Cooper said.

Philip Flynn, CEO of the $24 billion-asset Associated Banc-Corp in Green Bay, Wis., blamed heightened regulatory risk for dampening acquisitions, despite 2014 M&A activity being on pace to outstrip last year's volume.

"I'm not saying we will not do a transaction — at some point we will — but a deal will be driven by an interest to grow core-deposit funding. Buying someone else's problems, from a regulatory point of view, … is not attractive," Flynn said.

Andy Peters contributed to this article.

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