“Bets are up. Revenue is rising. And St. Louis is moving up on the list of the nation’s top gambling markets. Slot parlors are under construction on the banks of the Mississippi River. Two existing casinos are planning major expansions; a third just finished one.

“The result: Heated competition for a fast-growing, but not limitless, pool of gambling dollars. That has some observers wondering whether all of these bets on expansion will result in a payoff.

“?’The competition is going to be pretty heavy for that local dollar,’ said William Thompson, a public policy professor at the University of Nevada-Las Vegas and author of several books on gambling.

“?The St. Louis gambling market has grown rapidly since the Alton Belle opened as the region’s first casino in 1991.

“Today, the area has five casinos — two in Illinois and three in Missouri — and probably will exceed $1 billion in revenue for the first time this year. Local gambling revenue grew 13.1 percent to $959.6 million in 2005.

“The growth has surprised many experts who forecast a much smaller market than what has emerged.

“?They also cite the increasing popularity of gambling nationwide, a trend that will be further fueled by the retirement of millions of baby boomers.

“?Pinnacle plans to invest nearly $800 million to build new casinos in Lemay and downtown St. Louis over the next two years.

“In addition, Ameristar Casinos Inc. is building a $240 million, 400-room hotel at its casino in downtown St. Charles. The Casino Queen, a locally owned casino in East St. Louis, is spending more than $150 million to replace its aging riverboat with a barge in an inland moat. Harrah’s Entertainment Inc., meanwhile, finished a $65 million expansion of its Maryland Heights casino in late 2004?”