The threat of a strike was heightened yesterday when the board of the Metropolitan Transportation Authority angered transit union officials by approving its $9.3 billion budget for 2006 before settling contract negotiations.

The plan does not detail whether it contains money for wage increases for workers. The MTA board approved a spending plan to cover its $1.04 billion surplus, of which $705 million comes from a one-time windfall from tax revenue thanks to this year’s hot real estate market. The union has long sought part of the surplus for wage increases. Union officials raised questions over the size of the MTA’s projected surplus. They based their numbers on reports released Tuesday by the city’s Independent Budget Office that said revenue from real estate property taxes would be higher than initially expected.

The president of Local 100 of the Transport Workers Union, Roger Toussaint, said the surplus could be as much as $400 million higher – an amount that could be used to increase wages between 10% and 20%.”They are purposely hiding extra funds,” Mr. Toussaint said. Both the MTA and the city receive revenue from the same set of real estate property taxes – the mortgage recording tax and the real property transfer tax – but there are enough differences between how they are levied to make comparisons difficult, economists say. Mark Page, an MTA board member representing the mayor and the city’s budget director, quietly dismissed the union’s claim. “We’re actually more or less in sync in terms of our forecasts,” he said.

An economist and director of the Fiscal Policy Institute, James Parrot, said that after taking into account those differences, the authority could expect at least $200 million more in the next two years, an estimate he called conservative.