A couple of recently-announced mid-size bank deals may signal the Federal Reserve may be more supportive of regional bank mergers and acquisitions in the coming months. Three banks in particular could be possible takeover targets in 2015 as a result, according to The Deal's Ron Orol in Washington. Zions Bancorporation has a good footprint with franchises in valuable markets, but it's been forced to curtail its capital distribution to shareholders and conduct a $525 million share issuance to raise capital. That's left it unable to give shareholders adequate return on their investment. Comerica has underperformed in recent years and faces regulatory challenges from the Dodd-Frank Act. With $69 billion in assets and a strong presence in Texas, California and Michigan, a prospective buyer may want some, but not all of Comerica's assets.