A person is reflected in the window of a Wachovia Corp. branch office Monday in New York. Citigroup Inc. will acquire the banking operations of Wachovia Corp. in a deal facilitated by the Federal Deposit Insurance Corp.

Philadelphia ? Citigroup Inc.’s takeover of Wachovia’s banking business will create a triumvirate of behemoths controlling nearly a third of U.S. deposits.

This year’s massive consolidation – much of it pushed through on an emergency basis by regulators – is creating conditions that could eventually harm consumers and could lay the groundwork for an even bigger financial meltdown in the future, experts said.

“What’s most amazing to us is that there’s no public input or comment,” said Matthew Lee, executive director of Inner City Press/Fair Finance Watch. “We are basically living under banking martial law, and the public has to stay inside their homes,” he said.

Monday’s Citigroup-Wachovia deal, if it is approved by Wachovia shareholders, will give Citigroup a U.S. deposit market share of 9.79 percent, based on June 30 data from the Federal Deposit Insurance Corp.

Bank of America Corp., with its purchase of Countrywide Financial Corp. in July and its pending acquisition of Merrill Lynch & Co. Inc., is on its way toward 12 percent market share.

JPMorgan Chase & Co.’s purchase of the failed Washington Mutual Inc. boosted its market share to 9.75 percent.

Given the crisis mentality in Washington and New York, little attention is being paid to what Lee called an unprecedented level of consolidation.

U.S. Sen. Arlen Specter, R-Pa., said he is concerned about the concentration of banking power. “What the ramifications are, I’m trying to figure out,” said Specter, who is a member of the Senate Judiciary Committee’s Antitrust, Competition Policy and Consumer Rights subcommittee.

Specter said regulators are battling against deadlines to avoid bank failures. “They are rolling the dice to a certain extent on what the consequences might be,” he said.

Consumer advocates said bank customers will be worse off with giant banks exerting power over the market.

“Greater consolidation in the banking industry leads to fewer choices and higher fees for consumers,” said Ed Mierzwinski, consumer program director for U.S. Public Interest Research Group.

There is a downside for business, as well, said Robert White of Blue Bell Commercial Credit in Collegeville, Pa.

“We already have banks that are out of touch with their everyday clients, and when you create a behemoth you are just further alienating them,” said White, who helps smaller businesses get loans from banks.

Economists and finance experts were not so concerned about the consumer angle. They said there are still more than enough banks to ensure competition.

Their major concern is that the biggest banks are becoming unwieldy and too big to be transparent even to top managers, much less regulators. That increases the risk to our financial system, they said.

“If we have learned anything in the last six months,” said Cornelius Hurley, director of the Morin Center for Banking and Financial Law at the Boston University School of Law, “it is that some organizations are simply too big and too complex to manage, let alone to effectively supervise.”

Barry Bosworth, an economist at the Brookings Institution in Washington, shared a similar concern: “Large banks in themselves behave too much like lemmings” because of the way they set lending standards and propagate “credit quality problems from one market to another.”

Sandeep Dahiya, an associate professor of finance at Georgetown University, said that by allowing bigger and even more complicated financial institutions to form “we are doubling the stakes here for a future crisis.”

The key in the future is whether federal regulators are up to the challenge of the massive institutions they are midwifing into existence.