(Reuters) - Weir Group Plc (>> Weir Group PLC), a maker of pipes and valves for energy and mining industries, reported a 22 percent fall in full-year pretax profit, hurt by a weak North American oil and natural gas market.

Peer Petrofac Ltd (>> Petrofac Limited) said it saw an uptick in bidding activity in its core Middle Eastern markets.

Weir's shares fell as much as 3.5 percent before trading at 1961 pence. Petrofac shares rose as much as 4.5 percent before paring losses to trade at 900.9 pence on the London Stock Exchange.

"There is no doubt that over the last few months bidding activity has increased... we are seeing a number of projects deferred in 2016 coming back in 2017," Petrofac CFO Alastair Cochran told Reuters in a call.

The order book backlog at year-end for Petrofac's core engineering and constructions unit stood at $8.2 billion dollars (7 billion pounds) out of a total of $14.3 billion.

Petrofac, which design and maintenance provides services to oil and gas projects reported a 125.6 percent rise in its core earnings to $704 million for the year ended Dec. 31, as record production in the Middle East drove up contract awards.

Weir's full-year order input fell by 8 percent to 1.86 billion pounds, while revenue fell 11 percent to 1.85 billion pounds for the year, on a constant currency basis.

The Scottish company said its pretax profit fell to 170 million pounds ($212.3 million) for the year ended Dec. 31, from 219 million pounds reported a year earlier.

Peer John Wood Group Plc (>> John Wood Group PLC) had reported a 62 percent fall in its 2016 profit as weak oil prices continued to force oil producers to slash spending.

(Corrects paragraph 2 to remove reference to the reason for an uptick in bidding activity in Middle Eastern markets)

(Reporting by Sanjeeban Sarkar in Bengaluru; Editing by Amrutha Gayathri and Sunil Nair)

By Sanjeeban Sarkar

Stocks treated in this article : John Wood Group PLC, Petrofac Limited, Weir Group PLC