U.S. securities regulators will seek public comment on five proposals to curb short selling, blamed by some lawmakers and executives for deepening the financial crisis and driving down share prices.

The five-member Securities and Exchange Commission voted unanimously on Wednesday to seek 60-days of comment on five proposals, including bringing back an uptick rule -- allowing bets that a stock will fall only when the last sale price was higher than the previous price.

Another proposal would allow shorting only if the best available bid on a stock was higher than the last bid. Three other proposed restrictions would be triggered by a steep slide in the price of a security.

The SEC would have to vote again on any final rule, which could be modified in light of the comments it receives.

Traders and asset managers decried what they saw as scapegoating of short sellers for the plunge in stock prices that occurred as the housing market bubble burst and exposed risky bets by financial institutions.

The problem is that the managements of the banks and brokers screwed themselves up, short sellers did not, said hedge fund manager Doug Kass, who heads Seabreeze Partners Management.

Commissioners such as Kathleen Casey were generally skeptical of linking the 2007 abolition of the uptick rule to the last 18 months of stock market declines.

But SEC Chairman Mary Shapiro acknowledged the intense pressure on the agency to address short selling, telling Wednesday's meeting that no other issue had generated as many emails and comments since she took the position in January.

The commission is keenly aware of the need to balance the potential benefits of its proposed rules against the costs, she said.

Commissioner Luis Aguilar said he feared that even if the SEC adopted more short sale restrictions, the rules may not be effective, because investors could shift to unregulated financial products to bring a stock down.

Short interest on the New York Stock Exchange and Nasdaq Stock Market had fallen from highs in July until February, when it climbed back along with a rise in stock prices.

The SEC will hold a roundtable discussion of the issues on May 5. Any final action is at least two to three months away.

CONGRESSIONAL PRESSURE

The uptick rule was first adopted after the 1929 stock market crash but was abolished in 2007 after the SEC concluded that advances in the marketplace had rendered the rule ineffective and obsolete.

With the benchmark Standard & Poor's 500 index <.SPX> down roughly 45 percent since the start of 2008, and the Dow Jones Industrial Average <.DJI> down more than 40 percent over the same period, members of Congress and others have pressed for restoration of the rule.

We are pleased that the SEC has begun action against abusive short selling, said Senators Edward Kaufman, a Democrat, and Johnny Isakson, a Republican, who have introduced a bill requiring the SEC to reinstate the uptick rule and regulate abusive short selling activities.

Billionaire investor George Soros said on Monday that he favored a reintroduction of some kind of rule to restrict short selling. You do need to provide some protection against effectively the bear raids, Soros told Reuters Financial Television in an interview.

Short sellers argue that their trading helps keep markets liquid and prevents stocks from becoming overvalued. They also criticize last year's temporary ban on short sales of hundreds of financial stocks.

I am surprised that regulators have not learned from the (short-sale ban) fiasco where it ultimately reduced liquidity in the securities, said Ron Geffner, a partner at law firm Sadis & Goldberg LLP who advises hedge funds.

Market makers are not explicitly exempted under the rules proposed on Wednesday. The SEC said it would likely include several exceptions to the rules, but these exceptions would be limited to activities that promote liquidity and foster the workability of the proposed rules without undermining the effectiveness of the proposals.

SEC STAFF PREFER BID TEST

Erik Sirri, the SEC's trading and markets director, told reporters that staff at the agency prefer the bid test over the traditional uptick test as it would be easier to implement.

Sirri said the bid test made more sense as the tick test has a problem with getting an accurate tick given how quickly stocks trade.

Three other possible measures would use a circuit breaker approach to trigger a temporary suspension of short selling in a particular stock, or temporary application of the uptick or bid rule in a security.

Under one proposal, if a stock fell by 10 percent or some other amount, a circuit breaker would kick in and trigger the application of the bid test. The country's largest exchanges, the New York Stock Exchange, the Nasdaq Stock Market and BATS exchange, support a similar circuit breaker approach where shorting would only be allowed if the price was higher than the best available bid.

Another circuit breaker proposal would ban short selling in a particular stock for the rest of the day once triggered. A third circuit breaker proposal would trigger the application of the uptick rule for the rest of the day. The SEC is seeking comment on whether a decline of 10 percent is the proper threshold to trigger the application of a circuit breaker.

Casey, one of the commissioners who voted to abolish the uptick rule, said she had not yet been persuaded that its repeal had anything to do with the economic and market conditions of the past 18 months.

She also warned fellow commissioners that the courts could overturn a new SEC rule unless there was credible empirical evidence to demonstrate the repeal of the uptick rule, or abusive short selling, drove down the price of any security.

(Reporting by Rachelle Younglai and Karey Wutkowski; additional reporting by Jennifer Ablan and Jonathan Spicer in New York; Editing by Tim Dobbyn)

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