He also said that revenues from the express and parcel delivery service were rising at their strongest rate since the privatisation of CTT in 2014, with the last two quarters demonstrating "a more consistent and solid growth than in the past".

CTT on Wednesday posted a near 50 percent fall in first quarter net profit to 5.4 million euros (4.8 million pounds) largely due to restructuring costs and the drop in mail traffic - its main business, which is closely watched by analysts.

Still, mail revenues slipped only 0.8 percent thanks to more incoming international mail.

"I'm neither optimistic nor pessimistic, I'm keeping the (mail volume) guidance I gave in March," Lacerda said.

CTT shares fell over 2 percent at the open on Thursday on the back of the weak results, but later erased part of the losses to trade 0.9 percent lower at 11:20 a.m. (1020 GMT)

Express and parcel delivery revenues jumped almost 22 percent, partly thanks to the incorporation of the recently acquired Transporta business.

(Reporting By Sergio Goncalves, writing by Andrei Khalip, editing by Axel Bugge)