The size of mortgages that can be underwritten by Fannie Mae and Freddie Mac will increase in 71 metropolitan areas, including 221 counties and cities not in counties, according an announcement today from the Office of Federal Housing Enterprise Oversight.

The maximum for temporary jumbo conforming loan limits, which apply to loans originated in the period between July 1, 2007 and December 31, 2008, are as high as $729,750 for one-unit homes in the continental United States. The newly increased limits range from $417,500 in Greeley, Colorado to the highest of $793,750 in Honolulu, Hawaii.

Made possible by the Economic Stimulus Act of 2008, the rise in so-called conforming loan limits is based on media home prices within those metro areas as estimated by the U.S. Department of Housing and Urban Development.The new limits will remain in effect only through the end of 2008.