Philips Electronics NV has been forced to extend its $1.2bn offer to acquire San Jose-based chip maker VLSI Technology Inc until June 1 to clear up two regulatory problems that have arisen over the merger. It needs to satisfy the US government that the deal will not present national security concerns on VLSI’s government contracts, though Philips is confident an agreement can be reached. And, after calculating the two companies’ combined sales in Europe, Philips has found it needs to make an antitrust filing in Germany. Convincing the German government that the merger will not affect competition is necessary before clearance can be given by authorities in the European Union.