François Barrault likes to be the man who is unafraid to say no. The other day he walked out on an “egotistical” chief executive who didn’t understand what BT’s Global Services arm could offer him.

“He wanted to drive me nuts by buying my stuff as if it were dog food,” said an indignant Barrault, the Frenchman who for the past 14 months has led BT Global Services, the division that builds and runs communications networks for corporate customers and governments.

“He said: ‘Everybody wants my business!’ But when I think it’s not a good deal for us, I just walk away.”

Barrault is similarly dismissive of investment bankers who present him with endless takeover proposals. “They come to see you, do the belly-dance, do the deal, take the money, go to the beach,” he said. “Our business is much more longer-term, so some of them have had a very hard time with me.”

Barrault’s selective approach signals a new-found maturity for BT Global Services’ business — on track to become the company’s largest revenue-generating division this year.

Thanks to 8% top-line growth, it pulled in £7.9 billion in sales last year, 7% less than BT’s retail arm which, in Britain at least, is still the company’s most visible operation. The challenge now is to prove that Global Services — where customers include Novartis, KPMG and Thomson Reuters — can make a similar advance at the profit line. Without a mobile-phone arm, it is the growth engine fashioned for BT by Ben Verwaayen, the outgoing chief executive, who took his leave from the board last week.

At 11% last year, profit margins have been thin, compared with retail’s 18%. However, they are improving — up 40 basis points to 13.7% in the first three months of this calendar year. Barrault is conscious they must step up further, and is already looking beyond the long-held 15% target.

“When you have that, it’s a platform to go better. In this business, the price goes south, the currencies are up and down, but we need to offer better returns to our shareholders.”

His progress has yet to inspire BT’s share price, weighed down 26% so far this year by fears of increasing competition for broadband customers and future network-spending requirements.

“BT Global Services still has to prove itself by hitting the margin target,” said Richard Marwood at Axa Investment Managers. “We are wary that the quality of this new business and its profitability is not as good as the business that it is replacing.”

Unperturbed, Barrault is working hard to raise BT’s profile. The company is sponsoring the Montreux Jazz Festival, which starts this weekend. For the owner of a Steinway piano who writes his own music, the highlight is a 75th birthday party for Quincy Jones, the composer, arranger and music producer of albums by artists from Frank Sinatra to Michael Jackson.

At events such as these, Barrault can take the economic temperature felt by business leaders and government ministers. He has toured trade gatherings in the Middle East and Singapore recently, as well as hosting a conference in Las Vegas, where he introduced Neil Armstrong to emphasise BT would “go to the moon” for its customers.

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