According to a Reuters report, US District Court Judge James Moran backed a motion by TT to dismiss "most counts" in the countersuit brought against the vendor by Rosenthal.

Over the past year TT has sued a number of companies for infringing the US patent it holds for MD Trader, which displays multiple prices on a screen so that users can estimate the depth of a market. The system combines a static ladder price column with moving bid and ask data, together with a single order entry system.

But according to the report, Rosenthal Collins counter-sued TT for misuse of patents last year, alleging patent invalidity and misuse, deceptive business practices and unfair competition by the vendor.

Although Judge Moran dismissed most counts, he denied the motion to dismiss with respect to possible patent misuse by TT, deferring an opinion on "alleged overreaching" by the vendor.

TT has already secured a number of settlements and loyalty agreements with ISVs and broker-dealers - including Patsystems, FFastFill, Advantage Futures, Kingstree Trading and Goldenberg Hehmeyer. Most recently the vendor settled a patent claim with Man Group, which is now the largest futures broker, in a move that could lead to further high-profile legal action against other major exchanges and investment banks.

In December 2004 TT asked the four biggest futures exchanges for a slice of their revenues - a fee of 2.5 cents per side on all trades - in return for protection from patent lawsuits. Last year rumours surfaced that these claims had sparked the interest of the US Justice Department which is said to be investigating TT for possible monopoly abuse.

The vendor is still contesting a suit against bond trading network eSpeed and has filed other claims against ISVs GL Trade and Nyfix and futures dealer Peregrine Financial, among others.