NEW YORK (Reuters) - Spain and Ireland dodged a bullet on Wednesday when ratings agency DBRS stopped short of downgrading their debt below a European Central Bank trigger for extra charges to banks using the countries' bonds as collateral.

The ratings agency downgraded Spain to A (low) and held Ireland at the same rating, making DBRS the last of the four agencies used by the ECB to keep the sovereigns at the A level.

A drop below the A level would have led the ECB to charge banks an additional 5 percent penalty for using Spain's and Ireland's bonds as collateral.

The decision by DBRS comes after ECB President Mario Draghi raised expectations last week that the central bank could act soon to stem pressure that has made it costlier for fiscally troubled countries such as Spain to borrow money.

"It is clearly in the interest of the core of Europe to support the whole of the euro zone," said Fergus McCormick, the head of sovereign ratings for DBRS.

"We are assuming that there will be continued support of most if not all the members of the euro zone indefinitely. Otherwise these credits would be much lower because they're under major pressure."

The agency also downgraded Italy to A from A (high). Because Italy holds an A-minus rating from Fitch, the DBRS rating was not crucial to avoiding the ECB's punitive charge.

DBRS cited several factors in its downgrade of Spain, including a gloomier outlook for economic growth and resulting headwinds in closing a budget gap.

In contrast, DBRS cited Ireland for "tentative signs of stabilization,... progress reducing fiscal imbalances, and the restoration of lost competitiveness as reflected by two consecutive years of current account surpluses."

Nonetheless, the negative trends on all three ratings underscore the risks the euro zone debt crisis still poses, ranging from the hit to domestic demand to losses among regional trade partners.

"It's not only a homegrown risk now, it's also systemic, it's euro-zone wide," McCormick said of Spain.

DBRS gained significance in Europe at the start of 2008 when the ECB added it to the list of firms whose ratings govern which bonds can be used as collateral in its lending operations.

Moody's Investors Service rates Ireland Ba1; Standard & Poor's, BBB-plus; and Fitch, BBB-plus.

Spain is rated Baa3 from Moody's Investors Service, BBB-plus from Standard & Poor's; and BBB from Fitch.

Moody's Investors Service rates Italy Baa2 while Standard & Poor's rates the country BBB-plus.

(Reporting By Luciana Lopez; Editing by Padraic Cassidy and Dan Grebler)