The Commodity Futures Trading Commission (CFTC) is writing a host of new rules based on lessons learned from the 2007-09 financial crisis, which highlighted the opacity of derivatives and triggered a regulatory crackdown.

The rules for exchange-like platforms to trade swaps - which the commission is expected to vote on Thursday - will put an end to the bilateral trading between banks that was the norm before the crisis and which fuelled speculation and risk-taking.

"We will bring to this once-opaque market place the transparency that Congress and President Obama laid out," CFTC Chairman Gary Gensler said on a call with journalists.

The swaps market had modest beginnings in the 1980s, offering companies risk management tools, but rapidly started to attract speculators, causing it to mushroom out of sight of regulators in the following decades.

In an important nod to the industry - which is dominated by big banks such as Citigroup Inc (>> Citigroup Inc.), Bank of America Corp (>> Bank of America Corp) and JPMorgan Chase & Co (>> JPMorgan Chase & Co.) - the CFTC will continue to allow swaps deals to be negotiated over the telephone.

Derivative brokers such as ICAP PLC (>> ICAP plc), GFI Group Inc (>> GFI Group Inc.) and Tullett Prebon PLC (>> Tullett Prebon Plc) - who sign up for the bulk of trading between banks - had lobbied hard to retain so-called voice-broking, the core of their business.

The rules for the new platforms, called Swap Execution Facilities (SEF), were one of the last remaining building blocks in the CFTC's rules, part of the Dodd-Frank overhaul of the financial industry after the crisis.

The regulator has already sketched out how clearing houses need to stand between buyers and sellers of swaps to reduce risk and prevent market panic, and has adopted extensive requirements for data reporting.

Another compromise in the rules for SEFs was the minimum amount of quotes that a prospective client needs to get before entering a swap deal, a requirement that is aimed at bringing more transparency in the market.

The rules set a minimum of three quotes in so-called request-for-quote trading systems after a one-year phase-in period in which the minimum number of quotes is two. The CFTC had initially proposed a minimum of five quotes.

Critics of the industry had said the lower the number, the smaller the move away from bilateral trading.

The CFTC also determined the minimum size for large trades that may be reported with a delay - so-called block trades - so that buyers and sellers don't immediately show their hand and sway the market to their own disadvantage.

Using that rule, up to 14 percent of the market for interest rate swaps and credit default swaps would be counted as block trades in an initial phase-in period, after which it would drop to between 5 percent and 10 percent.

The commission's five members - three Democrats and two Republicans - are expected to vote on the proposals in a public hearing on Thursday, starting at 10 a.m. (4:00 p.m. British time).

(Reporting by Douwe Miedema; Editing by Stephen Coates)

By Douwe Miedema