Two Indiana business advocacy groups announced Thursday they have endorsed Sen. Richard Lugar, R-Ind., in his re-election bid.

The Indiana Chamber of Commerce and the Indiana Manufacturers Association said they are supporting Lugar, the sixth-term incumbent who is opposed in the May 8 primary election by second-term state Treasurer Richard Mourdock.

Lugar "has compiled a most impressive pro-economy, pro-jobs voting record throughout his years of service," Chamber President Kevin Brinegar said in a statement.

Brinegar cited Lugar's efforts to allow construction of the Keystone XL oil pipeline from Canada to the Gulf of Mexico, a proposal blocked by President Obama's administration, as an example of the senator's leadership.

Brinegar also said, "In a time when congressional approval levels are at record lows and partisanship is all too common, Sen. Lugar should be applauded for his ability to reach across the aisle and work with members of both parties."

According to Lugar's campaign, IMA President Patrick Kiely praised Lugar for supporting federal policies that helped protect 150,000 manufacturing jobs in Indiana during the recent economic recession.

The Chamber represents 5,000 member companies. The IMA represents 1,400 employers.

The Republican Senate nominee will face Rep. Joe Donnelly, D-2nd, in the November general election.