WCA Waste Corp.’s shareholders approved the company’s sale to Macquarie Infrastructure Partners II (MIP II).

Houston-based WCA's common stockholders will receive $6.50 per share in cash, all Series A preferred stock will be redeemed and WCA's existing credit facilities will either be partially or completely refinanced, the company said in a news release.

At the special meeting for the vote 29.9 million shares, or 87.3 percent of the firm’s outstanding common and preferred stock, were represented.

WCA expects the merger to be completed by the end of the first fiscal quarter of 2012.

New York-based MIP II, part of the Sydney-based Macquarie Group, agreed to buy WCA in December for approximately $526 million. MIP II will finance the transaction through a combination of shareholder capital and new underwritten credit facilities.

WCA ranked 18th on the Waste Age 100, with 2010 revenue of  $230 million and 1,286 employees. The company operates 25 landfills, 29 transfer stations and 29 collection operations. It serves approximately 450,000 customers in 14 states in the Southeast and Midwest U.S.