* Sees annual synergies of 120 mln Norwegian crowns
* Deal to be earnings positive from start
* Frank Mohn has higher operating margin than Alfa Laval average (Adds share price reaction, detail on acquired company)
STOCKHOLM, April 7 Swedish engineering group Alfa Laval said on Monday it had agreed to buy Norwegian marine and offshore pumping group Frank Mohn for 13 billion Norwegian crowns ($2.17 billion) in cash to boost its operations in the offshore oil and gas sector.
Alfa Laval has been highly acquisitive in building out its portfolio in heat transfer, centrifugal separation and fluid handling, buying around 20 companies in the last five years which had total sales of about 7.5 billion Swedish crowns ($1.15 billion).
Frank Mohn, based in Bergen, Norway and with approximately 1,200 employees, generated sales of 3.4 billion Norwegian crowns and had an order intake of 6.1 billion in 2013.
Alfa Laval, which had sales of 30 billion Swedish crowns in 2013, said the acquisition would be positive for earnings per share from the time of completion and would bring synergies of 120 million Norwegian crowns annually, gradually realized over a three-year period.
Profitability at Frank Mohn is above the average for the Alfa Laval group, the Swedish firm said.
Alfa Laval shares were up 2.2 percent at 181.60 crowns at 0716 GMT, outperforming a fall of 0.8 percent on the Stockholm blue-chip index.
The acquisition will expand Alfa's offering in fluid handling systems by adding industrial pumping to the existing range of equipment, which is currently focused on sanitary applications, Alfa said.
Frank Mohn sells pumping systems for offshore oil and gas installations and submerged cargo pumping systems for shippers.
The company is owned by Wimoh AS, a company controlled by the Mohn family.
($1 = 5.9970 Norwegian Krones) ($1 = 6.5481 Swedish Crowns) (Reporting by Simon Johnson; Editing by Erica Billingham)