The letter starts with Section 18 of the bill, which several groups have pointed out as a section that could allow banks to escape current business order patents. Several companies that hold these patents, related to check scanning processes and other technology, argue that financial services companies are hoping to use legislation to continue their so far unsuccessful efforts to litigate away these patents.

In contrast, the financial services industry supports the language as something that will allow the government to vacate "low quality" patents, which they define as patents that should never have been granted. In particular, language in the bill would allow patents to be challenged based on evidence of prior use or sale, which are factors that cannot be considered now under current rules.

"Section 18 establishes an unprecedented review procedure which would provide a 'third bite at the apple' to attack a targeted group of financially related business method patents that previously have been upheld through multiple examination, re-examination, and trial proceedings," the letter said. Industry observers say an amendment to the bill could be introduced at some point aimed at striking or modifying Section 18.

The letter also takes issue with the proposed change to a "first inventor to file" rule for determining who owns a patent. While this is seen by many as a way to harmonize the U.S. system with that used by the rest of the world, the letter warned about changing the U.S. practice so quickly.

"Several groups oppose H.R. 1249 because they view the change to first-to-file as a dangerous and unconstitutional effort to overturn 220 years of patent practice," it said.

Elsewhere, the letter rejects attempts to allow retroactive changes to pending patent enforcement actions, allow patent holders to make retroactive changes to their patent applications, and make it easier for non-patent holders to challenge patents based on "prior user rights" arguments.

House leaders are hoping to get to the bill later this week or possibly next week. The bill is largely similar to one the Senate approved earlier this year.