Now for the hard part.

Shareholders of Comcast Corp. and AT&T; Corp. yesterday approved Comcast's purchase of AT&T;'s cable business by wide margins.

The votes were largely preordained. Comcast president Brian L. Roberts controls about 87 percent of the voting shares of his company, so it was no surprise that 99.8 percent of the company's votes favored the merger.

Among AT&T; shareholders, who met yesterday in Charleston, S.C., 95 percent of votes cast were for the deal, currently valued at $49.1 billion.

With those votes behind him, Roberts moved a step closer to becoming the leader of the nation's largest cable company, which would have 22 million subscribers.

Approval by federal regulators is expected later this year, at which point Roberts must prove that bigger means better for shareholders and customers. His management team must merge the two companies without service problems; improve the profit margins at AT&T;'s cable systems; whack away at the debt the new company, AT&T; Comcast Corp., is taking on; and deal with consumers angry at what they see as an unbridled monopoly.

Roberts told shareholders who attended the company's annual meeting yesterday at Center City's DoubleTree Hotel that the company could meet all those challenges.

One shareholder told Roberts that he had had to call the company five times to get digital cable service at his home. He worried that the merger would only multiply such problems.

"I share that risk," the shareholder said, "but I would like to see you do better."

Roberts said it was hard to be perfect 100 percent of the time but added that the company had instituted a new system that measured how often Comcast resolved a customer's question in a single phone call.

Using what he said were conservative estimates, Roberts said Comcast should easily be able to improve operating profit margins at AT&T;'s cable systems from about 26 percent in 2003 to 36 percent in 2005. When it has acquired other systems, Comcast generally has improved margins to more than 40 percent.

That, along with cost savings that he expects to reach $500 million in 2005, should allow for 20 percent yearly growth in operating cash flow. Roberts emphasized that the numbers were not meant as a forecast but as a way of analyzing the deal.

As the country's largest cable company, AT&T; Comcast also will be able to market services such as its QVC shopping network and video on demand to a much larger audience.

"There's a terrific advertising opportunity that was never available to Comcast before," Roberts said.

AT&T; Comcast has arranged to borrow $17 billion to complete the deal, including $5 billion to modernize AT&T;'s cable systems. That will bring the new company's combined debt to $30 billion, a level that has rattled nerves on Wall Street.

Roberts, however, said AT&T; Comcast would be able to trim the debt back to previous levels by accomplishing three goals:

Microsoft Corp. already has agreed to convert $5 billion in AT&T; debt to equity in the new company.

Comcast owns about $2 billion in stock in AT&T;, Sprint PCS and other companies. The company has locked in the value of those securities and plans to sell them.

AT&T; Comcast hopes to get about $6.5 billion after taxes by selling its share of Time Warner Entertainment, which AT&T; partially owns and which operates HBO, Warner Bros. and some cable systems.

After the meeting, about 20 protesters, carrying signs that read, "This merger is off track. No more media monopoly. We want media democracy," attacked the deal.

Cheri Honkala, executive director of the Kensington Welfare Rights Union, said the merger could eliminate her group's ability to bring attention to the problems of the poor here. The group's Web site has won attention from reporters around the world, but she fears that AT&T; Comcast will increase the $40 a month it charges the group for cable access.

"This will take away from a voiceless constituency even more," Honkala said.

Cable companies generally have no direct cable competition in the markets where they operate. Roberts pointed out that while this deal dramatically expands Comcast's market, it doesn't eliminate competitors because his company's systems don't overlap AT&T;'s.

"I don't see how this reduces any competition just because we [will] own a cable system in Boston," he said.

Danielle Redden, campaign manager for the Philadelphia Community Access Coalition, said Comcast had not lived up to its obligation to create public-access channels in Philadelphia.

"It's an embarrassment. Their hometown, they don't have public access," Redden said.

Comcast regional vice president Ed Pardini said City Council would have to approve spending part of the $8 million in yearly franchising fees the company pays the city for public access. Redden acknowledged that City Hall has decided not to spend the money that way but said Comcast should get involved in encouraging the city to do so.