Alberta's budget surplus will be larger than expected again this year, but a government spokesman is warning that falling energy prices will limit the windfall to a few extra billion.

A report released in June by CIBC World Markets projected the surplus would reach a record $12 billion in 2008-09, based on soaring energy prices.

But provincial officials say those early predictions have been dampened by a drop in prices for oil and natural gas over the last several weeks.

The April budget foresaw a surplus of $1.6 billion — lower than the previous year's $4.6 billion.

A government source told The Canadian Press that this year's surplus will be higher than last year's, but nowhere near the $12 billion analysts were predicting.

Finance Minister Iris Evans is to release Alberta's first-quarter fiscal update Tuesday.