Now that Lucent Technologies Inc. and Alcatel SA have reached a definitive merger agreement, the two companies have their work cut out for them over the next year or so to make the deal work, according to one analyst.

“On paper, there is a good strategic fit between these two companies,” said Bertrand Bidaud, vice president of carrier operations and strategy at Gartner Inc. “The challenge, as always, is execution.”

Lucent and Alcatel agreed to a merger of equals on Sunday after more than a week of talks. Once the deal goes through, Alcatel shareholders will hold about 60 percent of the new company, which has combined annual revenue of