Johnson Matthey , the world's largest supplier of catalytic converters, beat forecasts with a 24 percent rise in first-half profit, helped by higher average metals prices, and said it expected results from the second half to be stronger.

The speciality chemicals companies said it saw an improved return on sales thanks to increased plant utilisation across the group and the effect of higher average precious metals prices over the period, which helped offset the impact of higher rare earth prices on parts of its autocatalyst business.

Underlying profit before tax came in at 203 million pounds, the company said on Wednesday, compared to a consensus of analysts' forecasts of 194.1 million, according to Thomson Reuters I/B/E/S.

Underlying earnings per share rose 29 percent to 72.8 pence, again just above expectations.

The short term prospects for the global economy are difficult to predict. Nonetheless we believe that Johnson Matthey is well placed and we currently anticipate that the group's results in the second half will be slightly ahead of those for the first six months of the year, Chief Executive Neil Carson said.

Notwithstanding current macroeconomic uncertainties, the drivers for our business remain robust.

The British speciality chemicals company said in July that its first half performance to the end of September would be significantly ahead of the year-ago period, thanks to resilient demand.

(Reporting by Clara Ferreira-Marques; Editing by Kate Kelland)