SAN ANTONIO, Texas (Reuters) - Radio operator Clear Channel Communications Inc (CCU.N) shareholders on Thursday approved its $17.9 billion takeover by private equity funds Thomas H. Lee Partners (THL.UL) and Bain Capital.

The vote ends a 20-month effort to take the radio and billboard operator private.

Clear Channel in a statement said that about 97 percent of the shares voted were cast in favor of the deal.

The parties intend to consummate the merger on Wednesday, July 30.

In May, the bank syndicate, private equity buyers and Clear Channel struck a deal to lower the deal's price and settle litigation between the parties.

The deal approved by shareholders, provided them with $36 a share, down from a $39.20 previously offered.

Regulators have approved the transaction, and the lenders have placed funding in escrow. Only a two-thirds approval vote by Clear Channel shareholders was needed to clear the deal.

In March, Thomas H. Lee Partners and Bain filed complaints in New York and Texas against the six Wall Street banks -- Citigroup Inc (C.N), Morgan Stanley (MS.N), Credit Suisse Group (CSGN.VX), Royal Bank of Scotland Group Plc (RBS.L), Deutsche Bank AG (DBKGn.DE) and Wachovia Corp (WB.N) -- to enforce their agreement to fund the buyout.

Central to the dispute was the hit the banks would take in funding the deal, given the deteriorated lending conditions.

(Writing by Sue Zeidler; editing by Carol Bishopric)