AT&T's business services division, the unit he heads, had been one of the US carrier's main bastions of growth, delivering much of the increased revenue needed to offset the company's shrinking residential long-distance business.

So when news emerged earlier this year that Mr Roscitt's division had also hit a rough patch, it was the final straw for many AT&T investors, leading to a slump in Ma Bell's stock price that has turned into the biggest crisis faced by Michael Armstrong since he was brought in to head the company.

Then, last weekend, the Financial Times reported that AT&T and British Telecommunications were having serious talks about combining their respective business services divisions into one stand-alone unit (along with a separate merger of their wireless businesses).

Interviewed beforehand, Mr Roscitt, under pressure from Wall Street to demonstrate that he can turn things around, is beginning to sound decidedly impatient himself.

"This is a $30bn business," he says of his division, which supplies nearly 45 per cent of AT&T's revenues. "I wish I could just snap my fingers and everything would be fixed, but it doesn't happen that quickly."

For an executive who had been seen as one of AT&T's rising stars, it has been a baptism of fire. Having built his reputation as head of AT&T Solutions, the outsourcing and IT services business that has become one of AT&T's best performers, Mr Roscitt was elevated at the start of this year to a new position in charge of all of the company's business services. He also continues to oversee the Solutions business.

Within weeks, however, he was faced with the first signs of the problems that were gathering. A series of job cuts, along with a reorganisation within the business division the previous summer, had left a confused and demoralised salesforce. To make matters worse, the upheaval came just as AT&T was handing the management of more than 250 of its biggest corporate accounts to Concert, the international joint venture with BT that began operations at the start of this year.

The internal problems caused by these changes came at a time when AT&T could ill afford to slip. Price declines in the traditional voice long-distance business were accelerating, says Mr Roscitt, as business customers began to rely more on their mobile phones and on the internet. And with a greater reliance on the voice business than its rivals, that hit AT&T particularly hard.

"When you get into a ditch like we're in, it takes longer than you think to get out," says Mr Roscitt. Wall Street's concerns that the problem may turn out to be deeper than AT&T first realised are unfounded, he adds. However, the bad publicity that has followed the setback has led some customers to delay decisions about buying new services, dragging out the slowdown.

To help put the business back on track, AT&T has revamped the compensation arrangements for its salesforce. Incentives have been changed to put more emphasis on sales of data and IP (internet protocol) services, and to reflect gains in revenue rather than volumes.

If that weren't enough to keep him busy, Mr Roscitt also sits on the board of Concert. Early rumblings suggest that not all has been sweetness and light at the new company as it struggles to find its feet and work out an operating arrangement with its two parents.

"There's always going to be noise in the system: it's normal with a start-up," says Mr Roscitt. "Everyone expects perfection from day one."

Longer term, he says that Concert "remains the right concept. You've got to play on the global landscape for big companies."

Despite that, it is not clear how Concert's business will develop in future, or what its final ownership structure will be.

AT&T has no plans to hand over further accounts to Concert, which at the same time is not trying to win new customers on AT&T's home turf, leaving a question over how the new venture can expand. "We may change our mind at some point in the future," concedes Mr Roscitt.

Also, the ultimate fate of the joint venture is far from clear. Global consolidation in the telecoms industry has gathered momentum since AT&T and BT first announced their plans, as was illustrated by the weekend's revelations. One possibility that has emerged this week is that the two companies' business services divisions might be combined with Concert, creating a single entity.

"Whether [Concert] stays [as it is] indefinitely, gets unleashed as a separate company, or gets folded into one of the parent companies, I can't say -I don't have a crystal ball," says Mr Roscitt. For now, though, he says that it is "premature" to consider an initial public offering (IPO) for Concert.

Nor does Mr Roscitt seem ready yet to consider an IPO for the jewel in his portfolio, the AT&T Solutions business - a unit that could be worth $30bn as a stand-alone company, according to Dan Reingold, telecoms analyst at Merrill Lynch. "It may make sense at some point, but I'm very cautious," the AT&T executive says.

Longer term, Mr Roscitt says he is intent on turning AT&T into one of the dominant companies in the business of managing and distributing content over the internet. Along with a handful of other big telecoms companies, AT&T has announced plans to move into businesses such as web hosting and content distribution that have been the preserve of independents such as Exodus and Akamai.

This is "a network game," he says: companies which own telecoms facilities will eventually be in a better position than specialists. To further its ambitions in this area, AT&T has also embarked on a range of alliances with big technology companies - an approach that Mr Roscitt says is a departure from AT&T's traditional go-it-alone preferences. "You're going to see us partner more aggressively," he adds.

While this may be laying the groundwork for the future, however, Ma Bell still has some serious repair work to do on its reputation in the short term.

"The market is not going to let up on us until we show back-to-back quarterly growth increases," says Mr Roscitt. "And that isn't going to happen for a while."