Kowloon Motor Bus (KMB) and its affiliate Long Win Bus (LWB) on Thursday announced a 4.2 percent pay rise for all staff, but the increase falls short of a hike of eight percent demanded by a labour union representing drivers.

The companies said the base salary for full-time monthly rate operation and maintenance employees will see a rise of at least HK$905. They also noted that a new bus captain can earn up to HK$27,300 per month on average.

"KMB and LWB continually invest in eco bus fleets and safety measures. In addition, with an expansion of the local railway, volatile international oil prices and a tight labour market, the bus industry is presented with profound challenges," the pair said in a statement.

They said the adjustment came after considering factors, including "the dedication, professionalism and perseverance" of their staff in the last three years.

The companies also said they would hope to enhance remuneration to retain workers.

The salary increase for operational and maintenance staff will be backdated to June 1, while the pay rise for clerical workers will come into effect on September 1.