Insurance company Alterra (ALTE) is rallying after Markel Corporation (MKL), a financial holding company, agreed to buy Alterra for $31 per share in cash and stock, or $3.13B. Each Alterra share will be exchanged for $10 and 0.04315 Markel shares, the companies said. In a note to investors earlier today, Wells Fargo analyst John Hall wrote that the acquisition of Alterra, which is based in Bermuda, should boost the share prices of other Bermuda based companies that are trading significantly below their book values. Allied World (AWH), AXIS Capital (AXS), Endurance Specialty (ENH), Montpelier Re (MRH), Platinum Underwriters (PTP), and Validus (VR) are examples of such companies, the analyst wrote. In early trading, Alterra surged 24.02% to $28.71, Allied World rose 1.89% to $80.15, Endurance Specialty gained 3.01% to $40.69, Montpelier Re added 1.97% to $22.78, Platinum Underwriters climbed 4.16% to $47.06, and Validus increased 1.54% to $34.85.