GDANSK/WARSAW (Reuters) -Poland’s biggest oil refiner PKN Orlen and number two player Grupa Lotos said on Thursday their management boards had approved plans for a merger first announced in 2018 but delayed by antitrust issues. Both refiners are state controlled and the merger is part of a wider plan by Poland’s ruling Law and Justice (PiS) party to increase control over the economy and build big national companies to better compete with global players. Shareholders of Lotos will get 1.075 shares of PKN for each Lotos share, the companies said. For the merger to take effect shareholders of bot…