Powered aerial work platforms renter Lavendon has unanimously rejected an "opportunistic" offer from joint bidders Ashtead Group and Belgium's Thermote & Vanhalst.It said the 115p a share offer, a 45% premium to the price on 2 December when Lavendon first attracted bid interest, "significantly undervalues" the business and it had "no hesitation" in turning down the proposal. TVH Services, the principal holding company of forklift truck and aerial platforms firm Thermote & Vanhalst, has already had two stabs at winning over Lavendon. A best offer of 111p a share was also rejected.Lavendon says trading since its last update on 16 November has been satisfactory and full-year results are expected to be in line with forecasts."Given the group's strong market positions and free cash flows, the board is confident that Lavendon is well placed to deliver significant value to shareholders over the medium term," it said Thursday.Ashtead wants to take on Lavendon's UK business and pay 47.5% of the £189m cost, while TVH will make up the rest for the bits in Europe and the Middle East."The joint acquirers have no expectation of making an offer above 115p per share unless due diligence reveals a material improvement in Lavendon's financial position and prospects versus current market expectations," read a statement earlier today. "There can be no certainty that any offer will ultimately be made even if the pre-conditions are met."