MEXICO — Selectmen and the Budget Committee kicked off the municipal budget-building process Thursday night.

Peter DeFilipp was chosen chairman of the Budget Committee and Betty Barrett, vice chairwoman.

Town Manager John Madigan said developing a budget isn’t getting any easier, particularly with state revenue-sharing continuing to decline. Between 2008 and 2011, revenue sharing dropped from about $600,000 to $400,000, he said.

The current municipal budget is $2.8 million; with school and Oxford County taxes, it’s $7.2 million. The tax rate is $23 per $1,000 of valuation.

Madigan said the county tax for 2012-13 is $82,582, up $8,682 from this year.

The school district has just begun its budget development process and will likely not have a final figure until June.

Officials decided to stay with an eight-member Budget Committee and not to invite representatives from social service agencies who are asking for town money to attend budget meetings. Instead, the letters requesting funds will be used to determine whether contributions will be placed on the town meeting warrant.

Budget meetings were set for March 20, 22 and 28. All begin at 6 p.m. and will be held in the Town Hall. If a fourth meeting is needed, it will be set later.

Factors affecting the 2012-13 budget include a 2 percent raise for all nonunion employees, and a 6.6 percent increase in the cost of health insurance premiums. Madigan said employees did not receive raises for the current year.

Once final municipal figures are determined by selectmen and the Budget Committee, a public hearing will be held. Residents of Mexico vote on town meeting articles through referendum.

Nomination papers are available for one seat on the Board of Selectmen that is held by Chairman Richard Philbrick, and one seat on the RSU 10 board held by Peter Zanoni. Both terms are for three years.

Nomination papers must be returned to the Town Office by April 27. The election will be held June 12.