EUROPEAN Central Bank council member Yves Mersch said the ECB will announce changes to its money-market rules in coming weeks to head off the risk of abuse by some financial institutions.

"At the margins there can still be cases where you see dangers of gaming the system," Mersch said in an interview on Saturday with Bloomberg News in Jackson Hole, Wyoming. "The governing council has been discussing the whole issue" and has agreed on a "certain amount" of refinement to the existing rules, he said.

ECB officials have become more concerned in recent months that banks are taking advantage of collateral rules that are broader than those used by the Federal Reserve and the Bank of England. The danger is that banks struggling to sell securities damaged by the credit-market rout will dump them on the ECB and become overly reliant on central bank funds.

Dutch policy maker Nout Wellink said in an interview with a newspaper published last Thursday that banks shouldn't become too dependent on the ECB for funding. Spain's Jose Manuel Gonzalez-Paramo said in June banks must make "serious efforts" to find buyers for asset-backed securities.

"It's not a broad-based revolution," said Mersch, who is attending a meeting of central bankers and financial officials organized by the Fed.

"We are satisfied with our framework. But since there are always on the margins evolutions we have to adjust our framework regularly to market practices."

"The precisions" planned by the ECB "concern some instruments," Mersch said, declining to elaborate. Unlike the Fed and the Bank of England, the ECB hasn't had to change its operation rules since the credit crisis began last year.

The ECB's response to any individual instances of abuse "would not necessarily be a question to be discussed publicly," he said. The central bank prefers to solve problems with "moral suasion."