But such persistent merger and acquisition activity creates some serious headaches too. Most of the small logistics and express specialists have a high profile in their niche markets or home countries. How do you rebrand them without losing either brand equity or customers?

A transitional plan usually allows the newly acquired company to retain its own identity. In the case of Exel's purchases this usually means tagging "an Exel company" to its name and logo. "We don't take every vehicle and change the livery immediately, but do it on a gradual basis. For example, when the company's letterhead runs out we replace it with Exel," Salt explains.

TNT has taken a similar approach. "We had an issue with our service provision in France. We bought a French company, Jet Services in 2000, which we merged into the group in 2002," says Andrew Huestis, marketing and communications director of TNT Express. "The company is called TNT Jet Services. Eventually it will become just TNT, but Jet Services had a better brand recognition than TNT, and we didn't want to lose the brand equity."

Although in these acquisitions the identity of the acquired company eventually disappears, the strength of the old company's brand is still important. UPS spokesperson Steve Holmes points to his company's acquisition of Fritz. "Fritz... was a very strong brand in the freight-forwarding arena. We felt comfortable with bringing Fritz under the UPS Supply Chain Solutions name because we knew its operational network was strong. Associating it more closely with the UPS name strengthened the breadth of value they offer because it is now combined with UPS’ global network and other expanded capabilities. Typically we leverage the UPS brand or we work to build it where it is not as well recognized as we would like it to be."

For Deutsche Post, however, the strength of the DHL brand when they bought the express delivery firm in was central to their strategy. "If we acquire medium or small companies the most important aspect is their service quality fitting in with our core brand values. In local companies, the brand is not strong and brand building is weak," says Beckmann. "We still analyze their brands and try to migrate their values to the global brand."

"We want to establish one global brand," says Deutsche Post's head of corporate marketing, Wolfgang Giehl. "That's one important aspect of buying DHL. Now we are putting all our activities under the one brand. At the end of the day it is easier to build one brand."

Deutsche Post merged all its logistics (previously Danzas) and express operations (DHL and Euro Express) under the single DHL brand on April 1. However, the transition period began months before when the Danzas brand symbols were redesigned in yellow. Now DHL has joined the yellow Deutsche Post family too.

Edwin Colyer is a science and technology writer based in Manchester, UK.