Delaware North Cos., the racetrack and casino operator, is updating its plans for a casino at Aqueduct racetrack in New York City but has still not finalized an agreement with the state on the casino's operation, officials for the company and Aqueduct said on Friday. Workers for the company have made several visits to Aqueduct within the last week to conduct architectural surveys, according to Ron Sultemeier, a Delaware North vice president, and Aqueduct officials. The workers updated architectural drawings and collected information for the company's zoning and permit applications, Sultemeier said. Delaware North was selected late last year to build and operate the casino. The company, however, has yet to sign a memorandum of understanding with the state that would allow construction to begin. Complicating the situation is the possibility that the state will approve slot machines at nearby Belmont Park, which would create competition for the Aqueduct casino. Sultemeier said that a range of issues are involved in negotiating the final agreement, including when the company would make a $370 million payment to the state that it pledged at the time it won the bid for the casino in October. Sultemeier said that none of the issues was threatening the viability of the company's proposal. "We're certainly spending a lot of money," Sultemeier said. "But there are still a lot of major steps to get done before we can put a shovel in the ground." Slot machines were legalized at nine New York racetracks, including Aqueduct, in 2001. The Aqueduct casino., however, has been stalled by political and financial issues surrounding the New York Racing Association, which operates Aqueduct, Belmont, and Saratoga.