In particular, Contact Energy, TrustPower, Vector and New Zealand Oil and Gas would be the most positively affected with New Zealand Windfarms also receiving a boost.
National intends to scrap the moratorium on thermal generation and encourage new gas-fired thermal generation to be built to ensure security of supply.
"National has concluded that gas will be a critical part of the generation mix.
"We believe this policy will be positive for Vector as embedded, or close-to-market gas generation at Rodney and Otahuhu will be constructed."
Vector would benefit in that its gas transmission assets and gas portfolio would become more valuable as gas demand in Auckland increased, he said.
Contact was likely to benefit through its ability to build more base load combined cycle gas turbines, while TrustPower was likely to be at a disadvantage, as gas generation would be built before wind generation.
National intended to target a 90% renewable generation future in combination with gas-fired generation to underpin security of supply.
The target would be secondary to security of supply, Mr Timms said.
Although ABN regarded that as a conflict with construction of gas generation plant, National was still likely to encourage renewables where possible.
"We see this as positive for Contact, through its geothermal strategy, and TrustPower, through its hydro and wind development portfolio."
The proposed changes to the Resource Management Act to ease the way for renewable electricity generation projects was also seen as positive for new generation projects, he said.
All generation companies should benefit through the significantly reduced time and costs of obtaining resource consents for projects.
National intended to encourage further oil and gas exploration, including deep water exploration.
ABN viewed that as positive for New Zealand Oil and Gas as it should create additional domestic exploration opportunities.
National announced it intended to introduce its own emissions trading scheme within nine months of being elected - assuming Labour did not pass its scheme before the election, Mr Timms said.
"No details of the scheme are outlined. We believe this will be a very tough process politically for National and is unlikely to be successful, given that Labour will have failed twice in its endeavours to introduce emission trading legislation."
No details of the scheme had been given except that no new coal stations would be introduced and Huntly would progressively be moved to reserve capacity.
The impact of the Huntly phase-out should be positive for Contact and TrustPower and negative for Solid Energy, the State-owned thermal coal producer.
The role of the Electricity Commission and overall governance of the electricity industry, including the role of the Commerce Commission, would be reviewed by a National government.
That could imply that the Electricity Commission was disestablished after the review, Mr Timms said.
Any softening of the Commerce Commission's regulatory control would have positive implications for Vector and Powerco.
Transpower's role as a system operator and monopoly supplier of electricity transmission would also be reviewed.
That could create opportunities for Vector and Powerco in the transmission services and asset management areas if the review highlighted a restructure of Transpower, he said.
