INVESTORS added £140 million to the stock market worth of Weir Group after the Glasgow engineer issued what an analyst reckoned amounted to an earnings upgrade.

Ahead of briefings with analysts yesterday Weir said it intended to re-confirm the guidance for its full year results which the company issued in May.

The group said then it had enjoyed a strong performance during the first quarter and continued to expect a year of "further good progress" in line with previous guidance.

However, investors were rattled by news in last month's interim management statement that order input in the key oil and gas division fell 26% on a like-for-like basis in the quarter. Weir noted then there was uncertainty about the market for pumps used in fracking for gas, following falls in the price of the commodity.

Yesterday, the company highlighted a strong performance by its minerals division.

The company told investors: "The minerals management team will highlight the market leadership positions in the division's core markets; its broadening and differentiated product and service offerings, and product innovation; and a number of future growth opportunities which are well developed."

Weir said the company's success in winning £1 billion orders for new equipment since January 2010 underpinned the division's ambition of doubling divisional 2011 operating profits by 2016.

Harry Phillips at Oriel Securities said: "They've put in a very punchy growth target for their minerals business which is in our view more than just a reiteration of guidance for the current year. It's a surprisingly up-tempo target they've set."

The update may help to offset concerns about the outlook for Weir generated by last month's IMS. The shares closed 66p firmer at 1503p.