By Lisa Lambert

WASHINGTON, May 24 (Reuters) - The U.S. House of Representatives will consider shaving $50 million off the budget of the top U.S. securities regulator, despite pleas to boost the agency's funding, in an appropriations hearing on Wednesday.

According to a summary of legislation released on Tuesday, the Financial Services Subcommittee will debate appropriating $1.5 billion for the Securities and Exchange Commission, which is $50 million below current levels and $226 million less than the amount President Barack Obama requested.

Funding would be focused on the SEC's "critical information technology initiatives and its economics division," according to the summary.

All spending bills begin in the House, which is controlled by Republicans.

The legislation goes beyond the SEC and encompasses funding for the Treasury Department, the Judiciary, and many other agencies concerned with financial regulation and taxes. In total, funding for all agencies in the measure would drop $1.5 billion. After the bill passes from committee, the entire House will vote on it.

Last month, SEC Chair Mary Jo White pressed Congress for an increase, saying the regulator needed hundreds more employees to carry out its core responsibilities and improve its information technology. It offsets taxpayer funds it receives with user fees and fines, and its spending does not affect the federal deficit.

The bill would also rescind leftover balances of the SEC's reserve fund, prohibit the regulator from requiring corporations to disclose political spending, and impose "reporting requirements to improve transparency, accountability, and fairness" from the agency.

The Internal Revenue Service would take one of the greatest hits in the bill, with the tax collector's budget shrinking $236 million to $10.9 billion, which is $1.3 billion less than Obama requested in his annual proposal.

The bill would also change the funding and organization of the Consumer Financial Protection Bureau, a watchdog created by the 2010 Dodd-Frank Wall Street reform law.

Many Republicans say the bureau reaches beyond its authority, unchecked by any external overseer. The legislation would end direct funding for the CFPB from the Federal Reserve and make its spending a part of the annual federal budget. At the same time, it would expand leadership of the agency from a single director to a five-member commission.

The bill would also require the agency to study the use of arbitration prior to issuing regulations. Earlier this month, the CFPB proposed blocking credit card companies, banks and other firms from forcing customers to waive their rights to join class action lawsuits and settle disputes only through arbitration.

(Editing by Frances Kerry)