(Reuters) - Commercial property data vendor CoStar Group Inc on Monday sweetened its offer to buy CoreLogic Inc by adding another $450 million, hoping to seal a deal and triumph over another competing bid by private equity firms. CoreLogic shares rose nearly 2% to $86 in trading before the bell. Under the new proposal, CoreLogic shareholders would receive $6 per share in cash and 0.1019 shares of CoStar’s common stock in exchange for each share of CoreLogic, totaling $90 per share. CoStar had made a $6.9 billion all-stock offer for CoreLogic last month, gatecrashing a smaller buyout deal between the real estate data provider and two private equity firms. Despite CoStar sweetening its bid by adding some cash, the primarily stock offer was still worth less on Monday than when it was unveiled on Feb. 16, because of the decline in CoStar’s shares. Still, on a per share basis, the offer is $10 higher than what CoreLogic agreed to sell itself to the private equity consortium. The takeover interest in CoreLogic came after activist investors Senator Investment Group LP and Cannae Holdings Inc began pushing the company to seek a sale by mounting their own acquisition bid, which they abandoned once the sale process got under way. A big part of CoreLogic’s business is thriving, as low interest rates have fueled a boom in parts of the property market. Reuters reported last week that CoreLogic had asked CoStar for more assurances that it can complete their combination should it attract antitrust scrutiny. CoStar on Monday said the merger does not present any meaningful antitrust concerns, adding, it will agree to an antitrust covenant that it will take all actions to obtain the required antitrust approvals.