The deal will add brands such as , and to 's operation, as well as giving it access to 15m potential users of OTC's sites and its partnerships with companies including Thomas Cook and Lunn Poly.
Brent Hoberman, chief executive officer of Lastminute.com, said the deal significantly strengthened the firm's place in the online travel market.
"The addition of OTC's established corporate and white label operations to Lastminute.com's leading branded consumer businesses will create an even more powerful force in the online travel and leisure sector," he said.
The company is expecting savings of 拢4m over the next financial year from the elimination of duplicate functions and improved operating efficiency.
The Lastminute deal values OTC shares at 31p each, representing a premium of 31.9% on OTC's closing market share price on Tuesday.
Mark Jones, chief executive officer of OTC, said: "This is an exciting combination of two significant e-travel players in Europe. There is a strong commercial rationale for the transaction and I expect our customers to benefit from the wider range and quality of travel products and services the combined group will offer."
Jones added that OTC shareholders were receiving an attractive premium and through their holding in Lastminute.com will have the opportunity to continue to participate in the high-growth online travel and leisure sector.
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