Porvair, the filtration and environmental tech group, has lifted its full year profit forecast as its metals filtration business continues to win market share.The division saw sales 13% ahead of the prior year in the nine months to the end of August, although the growth rate may slow as tougher comparisons kick in for the final quarter.Microfiltration revenues were 12% ahead during the period as new aerospace programmes and acquisitions drove earnings.Without giving firm figures, Porvair said profitability by the year's end will be "ahead of market expectations".Porvair currently has a market cap of £60m and has risen 61% in the last 12 months.BS