(Adds details from Rhodes' letter to DPS staff, paragraph 6)

By Suzannah Gonzales and Karen Pierog

May 3 (Reuters) - Detroit school teachers were expected to return to their classrooms on Wednesday following a two-day "sick-out" over paycheck concerns after receiving assurances from officials "they will be paid for their work," a union representative said.

Hundreds of teachers in Michigan's largest public school system called in sick beginning on Monday after hearing news the cash-strapped school system would run out of money to pay employees at the end of June.

The Detroit public school system, or DPS, with nearly 46,000 students, has been under state control since 2009 because of a financial emergency.

It will run out of money to pay employees after the fiscal year ends on June 30, the school system's state-appointed transition manager, former federal bankruptcy Judge Steven Rhodes, has said.

Detroit Federation of Teachers Interim President Ivy Bailey received a letter from Rhodes that "gave teachers and school employees the assurance they needed that they will be paid for their work," the union said in a statement.

Rhodes' letter to DPS staff, a copy of which the union provided to Reuters, said the school district would honor its "contractual obligation to pay teachers what they have earned."

At a membership meeting on Tuesday afternoon, union officials encouraged the school employees to return to classes on Wednesday.

DPS had no immediate comment.

Hundreds of teachers rallied outside school district offices earlier on Tuesday.

Michigan's House of Representatives Appropriations Committee on Tuesday approved a seven-bill package that would provide $500 million to aid the school district, which would be split into two entities, and make DPS eligible for a state loan.

It would also curb collective bargaining.

The proposed funding was less than the $715 million requested by Republican Governor Rick Snyder and approved by the Republican-controlled Senate as part of a different plan.

"Teachers, you are going to get paid," said State Representative Al Pscholka, the committee's chairman.

A spokesman for House Speaker Kevin Cotter said the full House, also controlled by Republicans, could take up the legislation as soon as this week. If passed, it would still need to be approved by the Senate and signed by Snyder.

Some Republicans criticized the sick-out, calling it an act of "educational malpractice."

"Teacher strikes are illegal in Michigan and that's just what this is. Teachers should be paid, but shutting down schools only causes harm to the children," Michigan Attorney General Bill Schuette said in a statement.