ANNAPOLIS - Gov. Martin O'Malley is expected to call a special session to expand gambling in Maryland -- including adding a casino in Prince George's County -- now that he has lined up the votes necessary for the legislation's approval, the speaker of Maryland's House of Delegates told lawmakers.

House Speaker Michael Busch, D-Anne Arundel, met with the House's Democratic leaders Wednesday afternoon to let them know of O'Malley's intentions. He said the governor believes he has secured the 71 votes in the House necessary for legislation authorizing a gambling expansion to succeed.

"I believe the governor has made that determination to go forward. I'm assuming that he believes the votes are there to pass legislation," Busch said. "I don't question that at all."

Gambling bills easily passed the state Senate votes during the regular 90-day General Assembly session.

A spokeswoman for the governor said no date for a session has been set.

The governor has until mid-August to call a special session and pass gambling legislation in time to place the issue on the November ballot.

Any expansion of gambling must be approved by voters statewide, and Busch said the legislation must include a local majority approval of Prince George's County residents to move forward.

O'Malley's staff has been preparing legislation that deals with the concerns some county delegations have with the effect a sixth state casino, which would be located in Prince George's County, may have on the state's original five casino sites.

Local revenue must be protected from any revenue lost by casinos because of competition from a Prince George's casino, Busch said, and a bill is expected to include the authorization of table games such as blackjack and roulette.

Busch said he would prefer lawmakers determine changes to the state's tax rate on slot machines -- currently set at 67 percent -- rather than create a gambling commission to set the rates in the future.

"I think the vast majority of people feel more comfortable with the legislature making a decision on the tax rates than a commission," Busch said.

Del. Curt Anderson, D-Baltimore, said he was not aware that the governor had rounded up the necessary number of votes in the House -- O'Malley has said he won't call a special session unless the success of a gambling bill was ensured.

"It's a big gamble," Anderson said.

The bill also should include a fair bidding process that includes the potential for a casino at National Harbor -- the most likely site -- and Rosecroft Raceway in Fort Washington, Busch said.