RICHMOND — Virginia’s revenue shortfall could grow by another $267 million over an October forecast issued by Gov. Tim Kaine, according to information Kaine shared Tuesday in a meeting with lawmakers, business leaders and economic advisers.

The new numbers could further complicate Kaine’s efforts to address a shortfall in the two-year, $77 billion budget that expires June 30, 2010. The governor will present a budget plan to lawmakers Dec. 17.

In October, Kaine called for spending cuts, nearly 600 layoffs and use of the state’s “rainy day” fund to save about $1 billion in the current fiscal year, and warned of deeper cuts in the second year of the budget cycle. At the time, Kaine pegged the shortfall at $2.5 billion.

But new information suggests the shortfall could reach about $2.8 billion. The estimate was based on an economic outlook by the firm Global Insight and developed by the Department of Taxation and an advisory board of economists.

Lawmakers in both houses already are anticipating a greater shortfall. The Senate Finance Committee said last month the shortfall could reach $3.5 billion once lawmakers account for new demands for health care and public safety.

The shortfall affects the general fund portion of the budget, which totals about $34.5 billion. Key income sources — mostly income and sales taxes — have not grown as expected when the budget was adopted earlier this year.

Key lawmakers and Kaine’s finance secretary said Tuesday that spending cuts will be severe in the fiscal year that begins July 1. Programs such as public schools and Medicaid, which largely have been spared in earlier rounds of budget cuts, could lose funding.

“Let’s face it, there will be layoffs, there will be activities that are eliminated in this budget,” said Secretary of Finance Richard Brown in a media forum sponsored by The Associated Press.