A coalition of the most influential trade groups in housing finance proposed a set of principals to regulators Monday, regarding upcoming rules and reform. The 16 trade groups urged government to ensure private capital plays a dominant role in the industry, and that it should bear the primary risk ahead of taxpayers. However, the groups also want  "continuing and predictable" government support that would keep investors confident and maintain enough liquidity for the market. Regulators and lawmakers are hitting critical crossroads laid out by the Dodd-Frank Act when the legislation was signed into law last summer. Rules regarding qualified residential mortgages, new servicing standards, and loan officer compensation are in the works. And policymakers are also undertaking a complete overhaul of the finance system to replace the giants Fannie Mae and Freddie Mac. The trade groups want to be sure the market has enough time to adjust to these historic changes. "Changes to the mortgage finance system must be done carefully and over a reasonable transition period to ensure that a reliable mortgage finance system is in place to function effectively in the years ahead," the coalition said. The trade groups include: American Bankers Association American Financial Services Association Community Mortgage Banking Project CRE Finance Council Housing Policy Council of the Financial Services Roundtable Independent Community Bankers of America Manufactured Housing Institute Mortgage Bankers Association Mortgage Insurance Companies of America National Apartment Association National Association of Realtors National Council of State Housing Agencies National Multi Housing Council Real Estate Roundtable Securities Industry and Financial Markets Association Write to Jon Prior. Follow him on Twitter @JonAPrior.