Salaries of full-time college faculty posted modest increases this year, though the gap between pay at private and public colleges continues to widen, a new report says.

Across all ranks and types of institutions, average salaries of full-time faculty rose 3.1 percent for the 2005-2006 academic year, but fell 0.3 percent when inflation is factored in, according to a report out Monday from the American Association of University Professors.

It was the second consecutive year of slight declines in inflation-adjusted wages for college faculty.

Salaries of full-time faculty who had been at the same institution the previous year, rose 4.4 percent, however. That's a 1-percent increase in real terms.

Salaries for such "continuing faculty" at private, non-church related colleges rose 4.8 percent, compared to 4.3 percent at public universities. Full professors earned average salaries of $111,817 at private colleges, compared to $91,367 at public universities and $82,804 at church schools.

Public colleges account for two-thirds of U.S. college faculty and three-quarters of students.

The survey does not include part-time faculty, who are generally paid at a much lower rate than full-time instructors and now account for 46 percent of faculty teaching, twice the level in 1971.

The release comes as a national commission is considering recommendations on higher education policy for Education Secretary Margaret Spellings. A recent paper issued by the commission, which has not made final recommendations, identifies faculty salary costs among the primary factors contributing to sharply rising tuition increases. The AAUP, however, says its data show a "long-term pattern of insufficient investment in faculty."