The Ladue School District will ask voters for a 49-cent operating tax increase in April.

The measure is aimed at offsetting some of the 9 percent decline in revenue during the last several years because of reductions in property assessments, officials said.

The school district's tax rate for 2011-12 is $3.10 per $100 of assessed valuation.

If voters reject the increase, the district will need to cut about $2.5 million to balance the 2012-13 budget, the district said today. Leaders have already cut about $7 million dollars in expenditures, or 14 percent of its annual expenditures, during the the last four years.

But district officials say increasing costs, such as utilities, insurance and retirement contributions, are beyond the district's control and offset many of the reductions each year.

Currently, the district is projected to have a negative unrestricted fund balance of more than $5.23 million by the 2015-16 school year.

In April 2010, voters approved a $32 million bond issue so the district could buy the former Westminster Christian Academy site to build an early childhood center, which opened this fall.

The School Board voted unanimously on the April ballot measure, called Proposition 1, this week.